anv: make input attachments available through bindless

anv: make input attachments available through bindless

With independent sets, we cannot bake into the shader the binding
table entry of input attachments anymore because that final location
is affected by multiple sets.

We can still access them by looking into the descriptor buffer. This
change enables the image handle to be stored in the descriptor buffer.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Emma Anholt <emma@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15637>