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>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 2aa0894..ea2d83d 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3085,7 +3085,8 @@
 	ret = drm_mm_insert_node_in_range_generic(&dev_priv->mm.gtt_space,
 						  &obj->gtt_space,
 						  size, alignment,
-						  obj->cache_level, 0, gtt_max);
+						  obj->cache_level, 0, gtt_max,
+						  DRM_MM_SEARCH_DEFAULT);
 	if (ret) {
 		ret = i915_gem_evict_something(dev, size, alignment,
 					       obj->cache_level,