drm/i915/display: Remove i915_gem_object_types.h from intel_frontbuffer.h

Now as we have removed all the references to internals of i915_gem_object
from the frontbuffer header we can also remove including
i915_gem_object_types.h.

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Jeevan B <jeevan.b@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727064142.751976-4-jouni.hogander@intel.com