panfrost: Add compiler args option for building usermode tools

Binaries built under src/panfrost weren't passed this compiler switch,
so it would trigger pointer arithmetic errors when using
the inlined definitions in the pandecode library.

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14034>

src/panfrost/meson.build

@@ -27,6 +27,10 @@ inc_panfrost = include_directories([
    '.', 'include', 'shared', 'midgard', 'bifrost', 'lib'
 ])
 
+compile_args_panfrost = [
+  '-Wno-pointer-arith'
+]
+
 subdir('shared')
 subdir('util')
 subdir('midgard')