panfrost: Fix CLAMP wrap mode

panfrost: Fix CLAMP wrap mode

MALI_WRAP_MODE_CLAMP doesn't work fully on either GPU generation, so
use other wrap modes instead in some cases.

With nearest filtering, Midgard only clamps to the edge for two of the
edges, and uses the border colour for the other two. Using the clamp
mode on Bifrost causes broken rendering and/or GPU faults.

Fixes piglit test "texwrap" on both Midgard and Bifrost, and fixes
Chromium B.S.U. rendering on Bifrost.

Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8176>