drm/radeon: use true,false for bool variable in ni.c

Fixes coccicheck warning:

drivers/gpu/drm/radeon/ni.c:2020:2-15: WARNING: Assignment of 0/1 to bool variable
drivers/gpu/drm/radeon/ni.c:2088:2-15: WARNING: Assignment of 0/1 to bool variable

Reported-by: Hulk Robot <[e-mail]>
Signed-off-by: zhengbin <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/radeon/ni.c

···
 		 * there. So it is pointless to try to go through that code
 		 * hence why we disable uvd here.
 		 */
-		rdev->has_uvd = 0;
+		rdev->has_uvd = false;
 		return;
 	}
 	rdev->ring[R600_RING_TYPE_UVD_INDEX].ring_obj = NULL;
···
 		 * there. So it is pointless to try to go through that code
 		 * hence why we disable vce here.
 		 */
-		rdev->has_vce = 0;
+		rdev->has_vce = false;
 		return;
 	}
 	rdev->ring[TN_RING_TYPE_VCE1_INDEX].ring_obj = NULL;