drm/exynos: remove DRM_FORMAT_NV12M from plane module

this patch removes DRM_FORMAT_NV12M from plane module because this format
is same as DRM_FORMAT_NV12. DRM_FORMAT_NV12M will be identified by
mode_cmd->handles and mode_cmd->offsets fields internally.
Signed-off-by: NInki Dae <inki.dae@samsung.com>
Signed-off-by: NKyungmin.park <kyungmin.park@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_plane.c

@@ -29,7 +29,6 @@ static const uint32_t formats[] = {
 	DRM_FORMAT_XRGB8888,
 	DRM_FORMAT_ARGB8888,
 	DRM_FORMAT_NV12,
-	DRM_FORMAT_NV12M,
 	DRM_FORMAT_NV12MT,
 };