drm/hisilicon/hibmc: Export VRAM MM information to debugfs

This change makes information about VRAM consumption available on
debugfs. See

  /sys/kernel/debug/dri/0/vram-mm

for an overview of how VRAM is being used.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203083819.6643-6-tzimmermann@suse.de

drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c

@@ -55,6 +55,7 @@ static struct drm_driver hibmc_driver = {
 	.desc			= "hibmc drm driver",
 	.major			= 1,
 	.minor			= 0,
+	.debugfs_init		= drm_vram_mm_debugfs_init,
 	.dumb_create            = hibmc_dumb_create,
 	.dumb_map_offset        = drm_gem_vram_driver_dumb_mmap_offset,
 	.gem_prime_mmap		= drm_gem_prime_mmap,