drm/radeon: add rdev in ring struct

Retrieving radeon device struct from ring struct will be
used in next patch where debugfs's show function can only pass
one private data pointer.
Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon.h

@@ -828,6 +828,7 @@ struct radeon_ib {
 };
 
 struct radeon_ring {
+	struct radeon_device	*rdev;
 	struct radeon_bo	*ring_obj;
 	volatile uint32_t	*ring;
 	unsigned		rptr_offs;

drivers/gpu/drm/radeon/radeon_ring.c

@@ -387,6 +387,7 @@ int radeon_ring_init(struct radeon_device *rdev, struct radeon_ring *ring, unsig
 	ring->ring_size = ring_size;
 	ring->rptr_offs = rptr_offs;
 	ring->nop = nop;
+	ring->rdev = rdev;
 	/* Allocate ring buffer */
 	if (ring->ring_obj == NULL) {
 		r = radeon_bo_create(rdev, ring->ring_size, PAGE_SIZE, true,