i965: Fold ABO state upload code into the SSBO/UBO state upload code.

i965: Fold ABO state upload code into the SSBO/UBO state upload code.

Having this separate could potentially make programs that rebind atomics
but no other surfaces ever so slightly faster.  But it's a tiny amount
of code to add to the existing UBO/SSBO atom, and very related.

The extra atoms have a cost on every draw call, and so dropping some of
them would be nice.  This also reclaims a dirty bit.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>