[PATCH v2 3/6] drm/fourcc: Add drm/vs tiled modifiers

[Simon Ser]

Would be good to have an overview comment to explain how bits in the
modifier are used and how everything is tied up together, e.g. what the
type and tile mode mean. Also some docs for DRM_FORMAT_MOD_VERISILICON_TYPE_NORMAL
would be nice. (If there is no other type, this can be removed, the bits
will be left as zero and can be extended later if needed.)