add GPS for nano g2

hardcoded interval of 1 minute after first fix obtained

variants/nano_g2_ultra/variant.h

@@ -130,11 +130,15 @@ External serial flash W25Q16JV_IQ
      * GPS pins
      */
 
+#define HAS_GPS 1
 #define GPS_L76K
 
 #define PIN_GPS_STANDBY (0 + 13) // An output to wake GPS, low means allow sleep, high means force wake STANDBY
 #define PIN_GPS_TX (0 + 9)       // This is for bits going TOWARDS the CPU
 #define PIN_GPS_RX (0 + 10)      // This is for bits going TOWARDS the GPS
+#define GPS_RX_PIN PIN_GPS_RX
+#define GPS_TX_PIN PIN_GPS_TX
+
 
     // #define GPS_THREAD_INTERVAL 50