r600g/radeonsi: Use caching buffer manager for textures as well

Significantly reduces BO allocation / destruction overhead for transfers,
e.g. measurable via x11perf -shm{ge,pu}t* with glamor.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>

src/gallium/drivers/radeon/r600_texture.c

@@ -633,7 +633,7 @@ r600_texture_create_object(struct pipe_screen *screen,
 	/* Now create the backing buffer. */
 	if (!buf) {
 		if (!r600_init_resource(rscreen, resource, rtex->size,
-					rtex->surface.bo_alignment, FALSE)) {
+					rtex->surface.bo_alignment, TRUE)) {
 			FREE(rtex);
 			return NULL;
 		}