Update #defines

External watchdog support was added (but never merged) for MeshTower V1. The update's V2's #defines to follow the conventions set there and piggy back off the support already written for V1.

variants/heltec_tower_v2/variant.h

@@ -82,10 +82,10 @@
 #define PIN_SERIAL2_RX (-1)
 #define PIN_SERIAL2_TX (-1)
 
-#define HAS_HARDWARE_WATCHDOG
-#define HARDWARE_WATCHDOG_DONE (0 + 9)
-#define HARDWARE_WATCHDOG_WAKE (0 + 10)
-#define HARDWARE_WATCHDOG_TIMEOUT_MS (8 * 60 * 1000)
+#define HAS_EXTERNAL_WATCHDOG
+#define EXTERNAL_WATCHDOG_DONE_PIN (0 + 9)
+#define EXTERNAL_WATCHDOG_WAKE_PIN (0 + 10)
+#define EXTERNAL_WATCHDOG_FEED_INTERNAL_MS (8 * 60 * 1000)
 
 #define SERIAL_PRINT_PORT 0