i965: Delete gen7_upload_sampler_state_table and vtable mechanism.

i965: Delete gen7_upload_sampler_state_table and vtable mechanism.

brw_upload_sampler_state_table now handles all generations, so we don't
need the vtable mechanism either.

There's still a lot of code duplication; the next patches will address
that.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>