i965: Use brw_upload_binding_table() for the pixel shader as well.

i965: Use brw_upload_binding_table() for the pixel shader as well.

This is not quite the same: brw_upload_binding_table() also has code to
early-return if there are no entries, while the existing code did not.

The PS binding table is unlikely to be empty since it will have at least
one color buffer.  If it ever is empty, early returning seems wise.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>