ipq807x: set interface for failsafe

Now that failsafe actually has working network interfaces, we need to set
the correct interface that is desired to serve for failsafe.

So, set the interfaces using the LAN networking config, it may need tweaking.

Signed-off-by: Robert Marko <robimarko@gmail.com>

target/linux/ipq807x/base-files/lib/preinit/06_set_preinit_iface_ipq807x.sh

@@ -0,0 +1,19 @@
+set_preinit_iface() {
+	. /lib/functions.sh
+
+	case $(board_name) in
+	edgecore,eap102|\
+	redmi,ax6|\
+	xiaomi,ax3600)
+		ifname=eth1
+		;;
+	qnap,301w)
+		ifname=eth3
+		;;
+	*)
+		ifname=eth0
+		;;
+	esac
+}
+
+boot_hook_add preinit_main set_preinit_iface