AP_HAL_Empty: remove unused write method

libraries/AP_HAL_Empty/RCOutput.cpp

@@ -20,9 +20,6 @@ void EmptyRCOutput::disable_ch(uint8_t ch)
 void EmptyRCOutput::write(uint8_t ch, uint16_t period_us)
 {}
 
-void EmptyRCOutput::write(uint8_t ch, uint16_t* period_us, uint8_t len)
-{}
-
 uint16_t EmptyRCOutput::read(uint8_t ch) {
     return 900;
 }

libraries/AP_HAL_Empty/RCOutput.h

@@ -11,7 +11,6 @@ class Empty::EmptyRCOutput : public AP_HAL::RCOutput {
     void     enable_ch(uint8_t ch);
     void     disable_ch(uint8_t ch);
     void     write(uint8_t ch, uint16_t period_us);
-    void     write(uint8_t ch, uint16_t* period_us, uint8_t len);
     uint16_t read(uint8_t ch);
     void     read(uint16_t* period_us, uint8_t len);
 };