anv: disable stencil pma fix on Gen > 9

This workaround isn't listed on Gen10.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/intel/vulkan/gen8_cmd_buffer.c

@@ -259,6 +259,8 @@ want_depth_pma_fix(struct anv_cmd_buffer *cmd_buffer)
 UNUSED static bool
 want_stencil_pma_fix(struct anv_cmd_buffer *cmd_buffer)
 {
+   if (GEN_GEN > 9)
+      return false;
    assert(GEN_GEN == 9);
 
    /* From the Skylake PRM Vol. 2c CACHE_MODE_1::STC PMA Optimization Enable: