drm/xe: KUnit tests depend on CONFIG_DRM_FBDEV_EMULATION

ERROR:root:../drivers/gpu/drm/xe/display/intel_fbdev.c:585:5: error: redefinition of ‘intel_fbdev_init’
  585 | int intel_fbdev_init(struct drm_device *dev)
      |     ^~~~~~~~~~~~~~~~
In file included from ../drivers/gpu/drm/xe/display/intel_fbdev.c:55:
../drivers/gpu/drm/xe/display/intel_fbdev.h:26:19: note: previous definition of ‘intel_fbdev_init’ with type ‘int(struct drm_device *)’
   26 | static inline int intel_fbdev_init(struct drm_device *dev)
      |                   ^~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.c:626:6: error: redefinition of ‘intel_fbdev_initial_config_async’
  626 | void intel_fbdev_initial_config_async(struct drm_device *dev)
      |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.h:31:20: note: previous definition of ‘intel_fbdev_initial_config_async’ with type ‘void(struct drm_device *)’
   31 | static inline void intel_fbdev_initial_config_async(struct drm_device *dev)
      |                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.c:646:6: error: redefinition of ‘intel_fbdev_unregister’
  646 | void intel_fbdev_unregister(struct drm_i915_private *dev_priv)
      |      ^~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.h:35:20: note: previous definition of ‘intel_fbdev_unregister’ with type ‘void(struct xe_device *)’
   35 | static inline void intel_fbdev_unregister(struct drm_i915_private *dev_priv)
      |                    ^~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.c:661:6: error: redefinition of ‘intel_fbdev_fini’
  661 | void intel_fbdev_fini(struct drm_i915_private *dev_priv)
      |      ^~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.h:39:20: note: previous definition of ‘intel_fbdev_fini’ with type ‘void(struct xe_device *)’
   39 | static inline void intel_fbdev_fini(struct drm_i915_private *dev_priv)
      |                    ^~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.c:692:6: error: redefinition of ‘intel_fbdev_set_suspend’
  692 | void intel_fbdev_set_suspend(struct drm_device *dev, int state, bool synchronous)
      |      ^~~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.h:43:20: note: previous definition of ‘intel_fbdev_set_suspend’ with type ‘void(struct drm_device *, int,  bool)’ {aka ‘void(struct drm_device *, int,  _Bool)’}
   43 | static inline void intel_fbdev_set_suspend(struct drm_device *dev, int state, bool synchronous)
      |                    ^~~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.c:751:6: error: redefinition of ‘intel_fbdev_output_poll_changed’
  751 | void intel_fbdev_output_poll_changed(struct drm_device *dev)
      |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.h:47:20: note: previous definition of ‘intel_fbdev_output_poll_changed’ with type ‘void(struct drm_device *)’
   47 | static inline void intel_fbdev_output_poll_changed(struct drm_device *dev)
      |                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.c:770:6: error: redefinition of ‘intel_fbdev_restore_mode’
  770 | void intel_fbdev_restore_mode(struct drm_device *dev)
      |      ^~~~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.h:51:20: note: previous definition of ‘intel_fbdev_restore_mode’ with type ‘void(struct drm_device *)’
   51 | static inline void intel_fbdev_restore_mode(struct drm_device *dev)
      |                    ^~~~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.c:785:27: error: redefinition of ‘intel_fbdev_framebuffer’
  785 | struct intel_framebuffer *intel_fbdev_framebuffer(struct intel_fbdev *fbdev)
      |                           ^~~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/xe/display/intel_fbdev.h:54:41: note: previous definition of ‘intel_fbdev_framebuffer’ with type ‘struct intel_framebuffer *(struct intel_fbdev *)’
   54 | static inline struct intel_framebuffer *intel_fbdev_framebuffer(struct intel_fbdev *fbdev)
      |                                         ^~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>