radv: Add workaround for hang in The Surge 2.

Released today and hangs on RADV. We don't have the root cause yet,
but this should unblock people playing the game.

No drirc because the radv debugflags are not usable from drirc and
I want this backported.

CC: <mesa-stable@lists.freedesktop.org>
Reviewed-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit 780182f0)