drm/radeon: init lockup timeout on ring init

Reset the lockup timeout on ring (re-)initialisation.

Otherwise we get error messages like this on gpu resets:
[ 1559.949177] radeon 0000:01:00.0: GPU lockup CP stall for more than 1482270msec
Signed-off-by: Christian König <deathsimple@vodafone.de>
cc: stable@vger.kernel.org
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>

drivers/gpu/drm/radeon/radeon_ring.c

@@ -706,6 +706,7 @@ int radeon_ring_init(struct radeon_device *rdev, struct radeon_ring *ring, unsig
 	if (radeon_debugfs_ring_init(rdev, ring)) {
 		DRM_ERROR("Failed to register debugfs file for rings !\n");
 	}
+	radeon_ring_lockup_update(ring);
 	return 0;
 }