v3dv/descriptor_set: added support for samplers

v3dv/descriptor_set: added support for samplers

This include SAMPLER, COMBINED_IMAGE_SAMPLER and SAMPLED_IMAGE
descriptors.

In order to support them we do the pre-packing of TEXTURE_SHADER_STATE
and SAMPLER_STATE when Images and Samplers (respectively) are
created. Those packets doesn't need to be tweaked later, so we upload
them to an bo.

A possible improvement of this would be that the descriptor pool
manages a bo for all descriptors, that suballocate for each descriptor
allocated. This is what other drivers do (and as far as I understand,
one of the reasons of having a descriptor pool).

Immutable samplers are not supported, will be handled on a following
patch.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6766>