drm/msm/dpu: drop wb2_formats_rgb

After enabling YUV support for writeback on a variety of DPU hardware,
the wb2_formats_rgb is now unused. Drop it following the report of LKP.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202503071857.oZbQsPaE-lkp@intel.com/
Reviewed-by: Rob Clark <robdclark@gmail.com> # on IRC
Patchwork: https://patchwork.freedesktop.org/patch/641848/
Link: https://lore.kernel.org/r/20250308-dpu-drop-wb2-rgb-v1-1-f5503fcd1bc2@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Author: lumag

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c

@@ -232,37 +232,6 @@ static const u32 rotation_v2_formats[] = {
 	/* TODO add formats after validation */
 };
 
-static const u32 wb2_formats_rgb[] = {
-	DRM_FORMAT_RGB565,
-	DRM_FORMAT_BGR565,
-	DRM_FORMAT_RGB888,
-	DRM_FORMAT_ARGB8888,
-	DRM_FORMAT_RGBA8888,
-	DRM_FORMAT_ABGR8888,
-	DRM_FORMAT_XRGB8888,
-	DRM_FORMAT_RGBX8888,
-	DRM_FORMAT_XBGR8888,
-	DRM_FORMAT_ARGB1555,
-	DRM_FORMAT_RGBA5551,
-	DRM_FORMAT_XRGB1555,
-	DRM_FORMAT_RGBX5551,
-	DRM_FORMAT_ARGB4444,
-	DRM_FORMAT_RGBA4444,
-	DRM_FORMAT_RGBX4444,
-	DRM_FORMAT_XRGB4444,
-	DRM_FORMAT_BGR888,
-	DRM_FORMAT_BGRA8888,
-	DRM_FORMAT_BGRX8888,
-	DRM_FORMAT_ABGR1555,
-	DRM_FORMAT_BGRA5551,
-	DRM_FORMAT_XBGR1555,
-	DRM_FORMAT_BGRX5551,
-	DRM_FORMAT_ABGR4444,
-	DRM_FORMAT_BGRA4444,
-	DRM_FORMAT_BGRX4444,
-	DRM_FORMAT_XBGR4444,
-};
-
 static const u32 wb2_formats_rgb_yuv[] = {
 	DRM_FORMAT_RGB565,
 	DRM_FORMAT_BGR565,