armvirt: add EFI support

EFI booting is used on newer machines compatible with the
Arm SystemReady specifications.

This commit restructures armvirt into a more 'generic'
target similar to x86.

See https://github.com/openwrt/openwrt/pull/4956
for a history of this port.

Signed-off-by: Mathew McBride <matt@traverse.com.au>

target/linux/armvirt/base-files/etc/board.d/02_network

@@ -0,0 +1,18 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+. /lib/functions/system.sh
+. /lib/functions/uci-defaults.sh
+
+board_config_update
+
+case "$(board_name)" in
+	traverse,ten64)
+		ucidef_set_interface_lan "eth0 eth1 eth2 eth3"
+		ucidef_set_interface_wan "eth6"
+		;;
+esac
+
+board_config_flush
+
+exit 0