pan/va: Permit encoding more flags

Missed the first time around.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15223>

src/panfrost/bifrost/valhall/valhall.py

@@ -161,6 +161,8 @@ class Staging:
         self.widen = False
         self.lanes = False
         self.lane = False
+        self.halfswizzle = False
+        self.combine = False
         self.size = 32
 
         if not self.flags: