ac/rgp: add missing include

The build would fail without this include if -std=gnu17 is used.

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/4057
Fixes: ffdfe136e67 ("ac/sqtt: move rgp/sqtt def to ac")
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8376>
1 file changed