nrf/drivers/softpwm: Rename init function to softpwm_init0.

ports/nrf/drivers/softpwm.c

@@ -79,7 +79,7 @@ static const pwm_events OFF_EVENTS = {
 #define active_events MP_STATE_PORT(pwm_active_events)
 #define pending_events MP_STATE_PORT(pwm_pending_events)
 
-void softpwm_init(void) {
+void softpwm_init0(void) {
     active_events = &OFF_EVENTS;
     pending_events = NULL;
 }

ports/nrf/drivers/softpwm.h

 #ifndef __MICROPY_INCLUDED_LIB_PWM_H__
 #define __MICROPY_INCLUDED_LIB_PWM_H__
 
-void softpwm_init(void);
+void softpwm_init0(void);
 void pwm_start(void);
 void pwm_stop(void);