AP_RCProtocol: added update() method for use by SITL

libraries/AP_RCProtocol/AP_RCProtocol.cpp

@@ -202,6 +202,11 @@ void AP_RCProtocol::check_added_uart(void)
     }
 }
 
+void AP_RCProtocol::update()
+{
+    check_added_uart();
+}
+
 bool AP_RCProtocol::new_input()
 {
     bool ret = _new_input;

libraries/AP_RCProtocol/AP_RCProtocol.h

@@ -47,6 +47,7 @@ public:
     void process_pulse(uint32_t width_s0, uint32_t width_s1);
     void process_pulse_list(const uint32_t *widths, uint16_t n, bool need_swap);
     void process_byte(uint8_t byte, uint32_t baudrate);
+    void update(void);
 
     void disable_for_pulses(enum rcprotocol_t protocol) {
         _disabled_for_pulses |= (1U<<(uint8_t)protocol);