Port the device mode demos to the XMEGA architecture where applicable.

Demos/Device/LowLevel/AudioInput/AudioInput.c

@@ -62,12 +62,14 @@ int main(void)
 /** Configures the board hardware and chip peripherals for the demo's functionality. */
 void SetupHardware(void)
 {
+#if (ARCH == ARCH_AVR8)
 	/* Disable watchdog if enabled by bootloader/fuses */
 	MCUSR &= ~(1 << WDRF);
 	wdt_disable();
 
 	/* Disable clock division */
 	clock_prescale_set(clock_div_1);
+#endif
 
 	/* Hardware Initialization */
 	LEDs_Init();