Revert accidental change to unsupported directory

Author: bulislaw

features/unsupported/net/eth/EthernetInterface/eth_arch.h

@@ -31,6 +31,11 @@ extern "C" {
 
 #if DEVICE_EMAC
 err_t emac_lwip_if_init(struct netif *netif);
+
+#else /* DEVICE_EMAC */
+void eth_arch_enable_interrupts(void);
+void eth_arch_disable_interrupts(void);
+err_t eth_arch_enetif_init(struct netif *netif);
 #endif
 
 #ifdef __cplusplus