tools/tinytest-codegen: Exclude ticks_diff test for qemu-arm port.

tools/tinytest-codegen.py

@@ -49,7 +49,7 @@ testgroup_member = (
 test_dirs = ('basics', 'micropython', 'extmod', 'inlineasm') # 'float', 'import', 'io', 'misc')
 exclude_tests = (
     'inlineasm/asmfpaddsub.py', 'inlineasm/asmfpcmp.py', 'inlineasm/asmfpldrstr.py', 'inlineasm/asmfpmuldiv.py', 'inlineasm/asmfpsqrt.py',
-    'extmod/time_ms_us.py',
+    'extmod/ticks_diff.py', 'extmod/time_ms_us.py',
     'extmod/ujson_dumps_float.py', 'extmod/ujson_loads_float.py',
     'extmod/uctypes_native_float.py', 'extmod/uctypes_le_float.py',
     'extmod/machine_pinbase.py', 'extmod/machine_pulse.py',