panfrost: Upload default sampler for txf

panfrost: Upload default sampler for txf

In NIR, txf does not take a sampler. However, in the hardware it does take a
sampler. If there is no sampler bound and we use txf, the hardware will read
back all-0's due to bounds checking. As a workaround, bind a trivial sampler and
use that.

As-is this workaround is Valhall specific, making use of an extra resource
table. I'm punting on generalizing back to Bifrost until I can discuss the issue
in more depth with Jason and Karol and figure out the right fix.

Fixes api.image_properties_query.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18656>