anv: Separate compute and graphics descriptor sets

anv: Separate compute and graphics descriptor sets

The Vulkan spec says:

    "pipelineBindPoint is a VkPipelineBindPoint indicating whether the
    descriptors will be used by graphics pipelines or compute pipelines.
    There is a separate set of bind points for each of graphics and
    compute, so binding one does not disturb the other."

Up until now, we've been ignoring the pipeline bind point and had just
one bind point for everything.  This commit separates things out into
separate bind points.

Tested-by: Józef Kucia <joseph.kucia@gmail.com>
Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102897
Cc: "18.0" <mesa-stable@lists.freedesktop.org>