esp32/mphalport: Add function to wake main from separate FreeRTOS task.

Signed-off-by: Andrew Leech <andrew.leech@planetinnovation.com.au>

ports/esp32/mphalport.c

@@ -214,7 +214,12 @@ uint64_t mp_hal_time_ns(void) {
     return ns;
 }
 
-// Wake up the main task if it is sleeping
+// Wake up the main task if it is sleeping.
+void mp_hal_wake_main_task(void) {
+    xTaskNotifyGive(mp_main_task_handle);
+}
+
+// Wake up the main task if it is sleeping, to be called from an ISR.
 void mp_hal_wake_main_task_from_isr(void) {
     BaseType_t xHigherPriorityTaskWoken = pdFALSE;
     vTaskNotifyGiveFromISR(mp_main_task_handle, &xHigherPriorityTaskWoken);

ports/esp32/mphalport.h

@@ -83,6 +83,7 @@ uint32_t mp_hal_get_cpu_freq(void);
 #define mp_hal_quiet_timing_exit(irq_state) MICROPY_END_ATOMIC_SECTION(irq_state)
 
 // Wake up the main task if it is sleeping
+void mp_hal_wake_main_task(void);
 void mp_hal_wake_main_task_from_isr(void);
 
 // C-level pin HAL