AP_HAL_VRBRAIN: rename enable_sbus_out to enable_px4io_sbus_out

libraries/AP_HAL_VRBRAIN/RCOutput.cpp

@@ -559,7 +559,7 @@ void VRBRAINRCOutput::_timer_tick(void)
 /*
   enable sbus output
  */
-bool VRBRAINRCOutput::enable_sbus_out(uint16_t rate_hz)
+bool VRBRAINRCOutput::enable_px4io_sbus_out(uint16_t rate_hz)
 {
     int fd = open("/dev/px4io", 0);
     if (fd == -1) {

libraries/AP_HAL_VRBRAIN/RCOutput.h

@@ -35,7 +35,7 @@ public:
     void set_output_mode(enum output_mode mode) override;
     
     void _timer_tick(void);
-    bool enable_sbus_out(uint16_t rate_hz) override;
+    bool enable_px4io_sbus_out(uint16_t rate_hz) override;
 
 private:
     int _pwm_fd;