r600: implement DDIV

Tested-by: Glenn Kennard <glenn.kennard@gmail.com>
Tested-by: James Harvey <lothmordor@gmail.com>
Cc: 17.0 <mesa-stable@lists.freedesktop.org>
(cherry picked from commit e4f8f9a638c1ffb9b76840b088290f11f0f91813)
1 file changed