nir/ntt/virgl: Add possibility to store image and atomics cs var offset in base and use this in NTT and virgl
With the correct base offset the host will be able to pick the right image/atomics array, and this fixes cases where images and image arrays with different access specifiers are used.
Fixes: KHR-GL43.shading_language_420pack.binding_image_array,
KHR-Single-GL43.arrays_of_arrays_gl.AtomicUsage