freedreno/isa: add bitmask_t to encode.py

Prep work for the next change.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11321>

src/freedreno/isa/encode.py

@@ -329,11 +329,16 @@ template = """\
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <util/bitset.h>
 
 <%
 isa = s.isa
 %>
 
+typedef struct {
+    BITSET_WORD bitset[BITSET_WORDS(${isa.bitsize})];
+} bitmask_t;
+
 /**
  * Opaque type from the PoV of generated code, but allows state to be passed
  * thru to the hand written helpers used by the generated code.