drm/ttm: use gfp_t instead of int for flags.

fixes sparse warning.
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/ttm/ttm_page_alloc.c

@@ -790,7 +790,7 @@ static int ttm_get_pages(struct page **pages, unsigned npages, int flags,
 	return 0;
 }
 
-static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
+static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, gfp_t flags,
 		char *name)
 {
 	spin_lock_init(&pool->lock);