tools/mpy-tool.py: Fix freezing of non-bytecode funcs with settrace.

Only bytecode functions can be profiled at this stage.  Native functions
(eg inline assembler) may not even have a valid prelude.

Fixes issue #5075.

tools/mpy-tool.py

@@ -412,6 +412,7 @@ class RawCode(object):
         print('    .fun_data_len = %u,' % len(self.bytecode))
         print('    .n_obj = %u,' % len(self.objs))
         print('    .n_raw_code = %u,' % len(self.raw_codes))
+        if self.code_kind == MP_CODE_BYTECODE:
             print('    #if MICROPY_PY_SYS_SETTRACE')
             print('    .prelude = {')
             print('        .n_state = %u,' % self.prelude[0])