i965: Combine BRW_NEW_*_BINDING_TABLE dirty bits.

i965: Combine BRW_NEW_*_BINDING_TABLE dirty bits.

A while back, we moved to directly emitting the Gen7+ state when
constructing the binding tables.  These flags are only used on
Gen4-6, which emit all the binding table pointers at once.

We gain nothing by having separate flags, so combine them.

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