lantiq: use the generic board detect

Drop the target specific detection function in favour of the generic
one provided by base-files.

Signed-off-by: Mathias Kresin <dev@kresin.me>

target/linux/lantiq/base-files/lib/preinit/01_preinit_board.sh

@@ -1,19 +0,0 @@
-#!/bin/sh
-
-lantiq_board_detect() {
-	name="$(strings /proc/device-tree/compatible | head -1)"
-	model="$(cat /proc/device-tree/model)"
-	[ -z "$name" ] && name="unknown"
-	[ -z "$model" ] && model="unknown"
-	[ -e "/tmp/sysinfo/" ] || mkdir -p "/tmp/sysinfo/"
-	echo $name > /tmp/sysinfo/board_name
-	echo $model > /tmp/sysinfo/model
-}
-
-do_lantiq() {
-	. /lib/functions/lantiq.sh
-
-	lantiq_board_detect
-}
-
-boot_hook_add preinit_main do_lantiq