i965/fs: Execute nir_setup_uniforms, _inputs and _outputs unconditionally.

i965/fs: Execute nir_setup_uniforms, _inputs and _outputs unconditionally.

Images take up zero uniform slots in the nir_shader::num_uniforms
calculation, but nir_setup_uniforms needs to be executed even if the
program has no non-image uniforms so the driver-specific image
parameters are uploaded.  nir_setup_uniforms is a no-op if there are
really no uniforms, so checking the num_uniform count is useless in
any case.

The nir_setup_inputs and _outputs changes shouldn't lead to any
functional change, they are just meant to preserve the symmetry
between them and nir_setup_uniforms.

Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>