all: Raise exceptions via mp_raise_XXX

  - Changed: ValueError, TypeError, NotImplementedError
  - OSError invocations unchanged, because the corresponding utility
    function takes ints, not strings like the long form invocation.
  - OverflowError, IndexError and RuntimeError etc. not changed for now
    until we decide whether to add new utility functions.
diff --git a/py/runtime.h b/py/runtime.h
index fe49288..428e257 100644
--- a/py/runtime.h
+++ b/py/runtime.h
@@ -149,8 +149,8 @@
 //NORETURN void nlr_raise_msg_varg(const mp_obj_type_t *exc_type, const char *fmt, ...);
 NORETURN void mp_raise_ValueError(const char *msg);
 NORETURN void mp_raise_TypeError(const char *msg);
+NORETURN void mp_raise_NotImplementedError(const char *msg);
 NORETURN void mp_raise_OSError(int errno_);
-NORETURN void mp_not_implemented(const char *msg); // Raise NotImplementedError with given message
 NORETURN void mp_exc_recursion_depth(void);
 
 #if MICROPY_BUILTIN_METHOD_CHECK_SELF_ARG