Factory reset GNSS_MODEL_MTK GPS modules with PCAS10,3 (#3388)

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/gps/GPS.cpp

@@ -1209,6 +1209,11 @@ bool GPS::factoryReset()
         // byte _message_CFG_RST_COLDSTART[] = {0xB5, 0x62, 0x06, 0x04, 0x04, 0x00, 0xFF, 0xB9, 0x00, 0x00, 0xC6, 0x8B};
         // _serial_gps->write(_message_CFG_RST_COLDSTART, sizeof(_message_CFG_RST_COLDSTART));
         // delay(1000);
+    } else if (gnssModel == GNSS_MODEL_MTK) {
+        // send the CAS10 to perform a factory restart of the device (and other device that support PCAS statements)
+        LOG_INFO("GNSS Factory Reset via PCAS10,3\n");
+        _serial_gps->write("$PCAS10,3*1F\r\n");
+        delay(100);
     } else {
         // fire this for good measure, if we have an L76B - won't harm other devices.
         _serial_gps->write("$PMTK104*37\r\n");