testsuite: give pre_cmd for mhu-perf 5x time

testsuite/tests/driver/multipleHomeUnits/mhu-perf/all.T

@@ -4,7 +4,7 @@ test('mhu-perf',
        pre_cmd('$MAKE -s --no-print-directory mhu-perf'),
        js_broken(22349),
        when(arch('wasm32'), skip), # wasm32 doesn't like running Setup/Makefile tests
-       pre_cmd_timeout_multiplier(2),
+       pre_cmd_timeout_multiplier(5),
        compile_timeout_multiplier(5),
      ],
      multiunit_compile,