drm/color-mgmt: Typo s/R332/RGB332/

drm/color-mgmt: Typo s/R332/RGB332/

Fix a typo of "RGB332" in kerneldoc for the drm_crtc_fill_palette_332()
helper.

Fixes: 7ff61177b7116825 ("drm/color-mgmt: Prepare for RGB332 palettes")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patch.msgid.link/c413e45c8f752a532a4ff377f7a8b9eaab4a082a.1776757681.git.geert+renesas@glider.be