py/scheduler: Add option to wrap mp_sched_schedule in arbitrary attr.

So ports can put it in a special memory section if needed.

py/mpconfig.h

@@ -1449,6 +1449,10 @@ typedef double mp_float_t;
 #define MICROPY_WRAP_MP_KEYBOARD_INTERRUPT(f) f
 #endif
 
+#ifndef MICROPY_WRAP_MP_SCHED_SCHEDULE
+#define MICROPY_WRAP_MP_SCHED_SCHEDULE(f) f
+#endif
+
 /*****************************************************************************/
 /* Miscellaneous settings                                                    */
 

py/scheduler.c

@@ -120,7 +120,7 @@ void mp_sched_unlock(void) {
     MICROPY_END_ATOMIC_SECTION(atomic_state);
 }
 
-bool mp_sched_schedule(mp_obj_t function, mp_obj_t arg) {
+bool MICROPY_WRAP_MP_SCHED_SCHEDULE(mp_sched_schedule)(mp_obj_t function, mp_obj_t arg) {
     mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION();
     bool ret;
     if (!mp_sched_full()) {