drm/i915: s/state/plane_state/

Use the canonical 'plane_state' name for function arguments
where appropriate.

Also do the s/int plane/int color_plane/ in couple of the
function prototypes while at it.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250213150220.13580-13-ville.syrjala@linux.intel.com


Reviewed-by: Jani Nikula <jani.nikula@intel.com>