drm/bochs: Drop fake gamma support

Only really needed for fbdev emulation at 8bpp. And bochs doesn't do
that. And either way bochs only does 32bit rgb, so this is all pretty
much wasted dead code.

The only consideration is that we need to not set up any gamma size
either.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Dave Airlie <airlied@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459331485-28376-5-git-send-email-daniel.vetter@ffwll.ch

drivers/gpu/drm/bochs/bochs_fbdev.c

@@ -162,22 +162,7 @@ static int bochs_fbdev_destroy(struct bochs_device *bochs)
 	return 0;
 }
 
-void bochs_fb_gamma_set(struct drm_crtc *crtc, u16 red, u16 green,
-			u16 blue, int regno)
-{
-}
-
-void bochs_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
-			u16 *blue, int regno)
-{
-	*red   = regno;
-	*green = regno;
-	*blue  = regno;
-}
-
 static const struct drm_fb_helper_funcs bochs_fb_helper_funcs = {
-	.gamma_set = bochs_fb_gamma_set,
-	.gamma_get = bochs_fb_gamma_get,
 	.fb_probe = bochsfb_create,
 };