drm/mm: add "best_match" flag to drm_mm_insert_node()

Add a "best_match" flag similar to the drm_mm_search_*() helpers so we
can convert TTM to use them in follow up patches. We can also inline the
non-generic helpers and move them into the header to allow compile-time
optimizations.

To make calls to drm_mm_{search,insert}_node() more readable, this
converts the boolean argument to a flagset. There are pending patches that
add additional flags for top-down allocators and more.

v2:
 - use flag parameter instead of boolean "best_match"
 - convert *_search_free() helpers to also use flags argument

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/ttm/ttm_bo_manager.c

@@ -69,7 +69,8 @@ static int ttm_bo_man_get_node(struct ttm_mem_type_manager *man,
 		spin_lock(&rman->lock);
 		node = drm_mm_search_free_in_range(mm,
 					mem->num_pages, mem->page_alignment,
-					placement->fpfn, lpfn, 1);
+					placement->fpfn, lpfn,
+					DRM_MM_SEARCH_BEST);
 		if (unlikely(node == NULL)) {
 			spin_unlock(&rman->lock);
 			return 0;