Implement rmtLoop to be able to continuously send pulses (#3650)

Number of pulses is limited to the reserved RMT memory for the channel. Very useful for PWM, Servo and other repeatable signals.

cores/esp32/esp32-hal-rmt.h

@@ -73,6 +73,12 @@ float rmtSetTick(rmt_obj_t* rmt, float tick);
 */
 bool rmtWrite(rmt_obj_t* rmt, rmt_data_t* data, size_t size);
 
+/**
+*    Loop data up to the reserved memsize continuously
+*
+*/
+bool rmtLoop(rmt_obj_t* rmt, rmt_data_t* data, size_t size);
+
 /**
 *    Initiates async receive, event flag indicates data received
 *