drm/i915: Introduce intel_crtc_needs_color_update()

Add a common helper to answer the question "do we need
to update color management stuff?".

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221021162442.27283-5-ville.syrjala@linux.intel.com