ath25: fix preinit Ethernet port configuration

vconfig is no more installed by default to a firmware image. So, replace
vconfig calls for VLAN subinterface configuration by coresponding
ip-link commands.

Also drop few useless comments from the preinit hook script, while we
are at it.

I have no chance to test this fix since I have no board with a subject
switch IC, but this is still better then call an utility that is
unavailable in the firmware for years.

Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
[use documented syntax for ip link add]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/ath25/base-files/lib/preinit/15_preinit_iface_atheros

@@ -1,12 +1,10 @@
-# reset button only supported on ar5315+ at the moment
 preinit_ip() {
 	if [ -z "$pi_ifname" ]; then
 		grep -q 'Atheros AR231[567]' /proc/cpuinfo && {
 			if [ -e "/sys/bus/mdio_bus/drivers/Infineon ADM6996/0:00" -o \
 			     -e "/sys/bus/mdio_bus/drivers/Marvell 88E6060/0:10" ]; then
-				vconfig set_name_type DEV_PLUS_VID_NO_PAD
 				ip link set eth0 up
-				vconfig add eth0 1
+				ip link add link eth0 name eth0.1 type vlan id 1
 				ifname=eth0.1
 			else
 				ifname=eth0
@@ -20,13 +18,10 @@ preinit_ip() {
 	}
 }
 
-
-# reset button only supported on ar5315+ at the moment
-
 preinit_ip_deconfig() {
 	if [ -e "/sys/bus/mdio_bus/drivers/Infineon ADM6996/0:00" -o \
 	     -e "/sys/bus/mdio_bus/drivers/Marvell 88E6060/0:10" ]; then
-		vconfig rem eth0.1 2>/dev/null
+		ip link del eth0.1 2>/dev/null
 		ip link set $pi_ifname down
 	elif [ -n "$pi_ifname" ]; then
 		ip -4 addr flush dev $pi_ifname