add XL as gpio

modules/XL_as_gpio/XL_as_gpio.ino

+//sec 2017
+
+void setup() {
+  //Need to switch to internal LFCLK to disconnect from XL1 and XL2
+  NRF_CLOCK->LFCLKSRC = 0; //disconnect XL1 AND XL2 FROM LFCLK
+  NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
+  NRF_CLOCK->TASKS_LFCLKSTART    = 1;
+  while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0){}
+
+  //now can use XL1 and XL2 as usual gpio
+}
+
+void loop() {}