minigbm: dri: Support 2+ planes query for modifiers.

If the driver does not implement the new function, or
if modifier is INVALID this should return exactly the
same as before.

For LINEAR, DRI should return exactly the same as
minigbm for all the YUV formats.

BUG=b:149819940
TEST=Use with followup patch and login on a Zork device + play a YT
video.

Change-Id: I6ea3b5827876844e510794b85212be51e5dfd68f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/minigbm/+/2093211
Tested-by: Bas Nieuwenhuizen <basni@chromium.org>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
Commit-Queue: Bas Nieuwenhuizen <basni@chromium.org>
diff --git a/dri.h b/dri.h
index 9c72b1e..d424dfc 100644
--- a/dri.h
+++ b/dri.h
@@ -34,5 +34,6 @@
 int dri_bo_destroy(struct bo *bo);
 void *dri_bo_map(struct bo *bo, struct vma *vma, size_t plane, uint32_t map_flags);
 int dri_bo_unmap(struct bo *bo, struct vma *vma);
+size_t dri_num_planes_from_modifier(struct driver *drv, uint32_t format, uint64_t modifier);
 
 #endif