favr-32: Remove deprecated call

at32_add_system_devices() is deprecated, so remove the call to it.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

arch/avr32/boards/favr-32/setup.c

@@ -327,8 +327,6 @@ static int __init favr32_init(void)
 
 	at32_select_gpio(GPIO_PIN_PB(3), 0);	/* IRQ from ADS7843 */
 
-	at32_add_system_devices();
-
 	at32_add_device_usart(0);
 
 	set_hw_addr(at32_add_device_eth(0, &eth_data[0]));