drm/i915: Clean up intel_color_init_hooks()

Remove a bunch of pointless curly brackets and do
the s/dev_priv/i915/ while at it.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220929071521.26612-5-ville.syrjala@linux.intel.com


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