drm/radeon: disable UVD advanced semaphore mode

Not needed and seems to cause some problems.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/r600.c

@@ -2625,7 +2625,7 @@ int r600_uvd_rbc_start(struct radeon_device *rdev)
 	radeon_ring_write(ring, 0x8);
 
 	radeon_ring_write(ring, PACKET0(UVD_SEMA_CNTL, 0));
-	radeon_ring_write(ring, 1);
+	radeon_ring_write(ring, 3);
 
 	radeon_ring_unlock_commit(rdev, ring);