softpipe: Fix swizzled texture gather of int textures.

softpipe: Fix swizzled texture gather of int textures.

We need to pick 1u vs 1.0f based on the type of the texture, just like for
normal samples.  Move the decision up to the create_sampler_view, and use
that value from both sampler paths.

Cc: mesa-stable
Reviewed-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8012>