v3d/tex: don't configure tmu config 1 if not needed

v3d/tex: don't configure tmu config 1 if not needed

TMU configuration parameter 1 configures the sampler for the texture
operation. But there are some texture operations that doesn't need a
sampler. Skipping the configuration could provide a small perf
improvement on OpenGL. On the incoming Vulkan driver, would allow us
to avoid to set up an unneeded sampler.

Note that we still need to add the sampler configuration parameter if
the output is a 32bit, as it is on the sampler where we configure that
info.

Also, note that for images this is done comparing against a unpacked
p1 default. But in order to do that it is needed to go through the
code that fills up the unpacked p1. We can skip that too.

Reviewed-by: Eric Anholt <eric@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4677>