amdgpu/dm: constify yuv_formats.

Signed-off-by: NDave Airlie <airlied@redhat.com>
Reviewed-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -3073,7 +3073,7 @@ static uint32_t rgb_formats[] = {
 	DRM_FORMAT_ABGR2101010,
 };
 
-static uint32_t yuv_formats[] = {
+static const uint32_t yuv_formats[] = {
 	DRM_FORMAT_NV12,
 	DRM_FORMAT_NV21,
 };