intel/compiler: Track lower_dpas flag in brw_get_compiler_config_value

This user-settable flag affects compiler output, so it should be tracked
in the cache hash.

Fixes: 3756f60558 ("intel/fs: DPAS lowering")
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Suggested-by: Lionel Landwerlin
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26993>

src/intel/compiler/brw_compiler.c

@@ -249,6 +249,8 @@ brw_get_compiler_config_value(const struct brw_compiler *compiler)
 
    insert_u64_bit(&config, compiler->precise_trig);
    bits++;
+   insert_u64_bit(&config, compiler->lower_dpas);
+   bits++;
 
    uint64_t mask = DEBUG_DISK_CACHE_MASK;
    bits += util_bitcount64(mask);