drm/radeon: stop including swiotlb.h

radeon does not need swiotlb.h, so stop including it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_ttm.c

@@ -36,7 +36,6 @@
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/swap.h>
-#include <linux/swiotlb.h>
 
 #include <drm/drm_device.h>
 #include <drm/drm_file.h>