radv: Use correct HTILE expanded words.

Seems like users are actually hitting 0xFFFFFFFF actually making
things broken for them, and the mad max regression is fixed, so
lets put this in once more.

v2: Use 0xf for depth-only htile. (Dave)

Fixes: af284411 "radv: Revert HTILE reset word to 0xFFFFFFFF."
Reviewed-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit 51586031)