Rover: updates for new RCInput API

APMrover2/radio.pde

@@ -45,7 +45,7 @@ static void init_rc_out()
 
 static void read_radio()
 {
-    if (!hal.rcin->valid_channels()) {
+    if (!hal.rcin->new_input()) {
         control_failsafe(channel_throttle->radio_in);
         return;
     }

APMrover2/test.pde

@@ -104,7 +104,7 @@ test_passthru(uint8_t argc, const Menu::arg *argv)
 		delay(20);
 
         // New radio frame? (we could use also if((millis()- timer) > 20)
-        if (hal.rcin->valid_channels() > 0) {
+        if (hal.rcin->new_input()) {
             cliSerial->print("CH:");
             for(int i = 0; i < 8; i++){
                 cliSerial->print(hal.rcin->read(i));	// Print channel values