drm/i915/params: Align visibility of device level and global modparams

We have a few modparams which get conditionally exposed based on a Kconfig
options and in most cases this also means portions of the driver
implementing the respective feature are also left out.

Align the visibility of device level and global modparams to make them
consistent in this respect.

v2:
 * Fix misplaced parentheses.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210526141946.2347085-1-tvrtko.ursulin@linux.intel.com