mediatek: do not create device nodes in uci-defaults script

Since commit 298814e6be ("base-files: config_generate: split macaddr with
multiple ifaces") uci MAC address setup will create a device node for each
member iface. But this script might override the device nodes and interfere
with the MAC address setup.

Signed-off-by: Sungbo Eo <mans0n@gorani.run>

target/linux/mediatek/base-files/etc/uci-defaults/99-net-ps

@@ -1,16 +1,5 @@
-uci set network.globals='globals'
-uci set network.globals.packet_steering=1
-uci set network.eth0=device
-uci set network.eth0.name=eth0
-uci set network.lan0=device
-uci set network.lan0.name=lan0
-uci set network.lan1=device
-uci set network.lan1.name=lan1
-uci set network.lan2=device
-uci set network.lan2.name=lan2
-uci set network.lan3=device
-uci set network.lan3.name=lan3
-
-uci commit network
-
-exit 0
+uci -q get network.globals.packet_steering >/dev/null || {
+	uci set network.globals='globals'
+	uci set network.globals.packet_steering=1
+	uci commit network
+}