freedreno/a5xx: fix page faults on last level

We could alternatively fall back to using "old style" draw's for
mem<->gmem (ie. what <= a4xx do) when height is not aligned to 32,
but that is somewhat more work (and not really something that could
be applied to stable)

Cc: "18.0" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
(cherry picked from commit 1866f76f)