treewide: do board detection during preinit

Do the board detection during preinit to unify it across all targets.

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

target/linux/orion/base-files/lib/preinit/01_sysinfo

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+do_sysinfo_orion() {
+	local name="$(sed -n /Hardware/s/.*:.//p /proc/cpuinfo)"
+	[ -z "$name" ] && name="unknown"
+
+	[ -e "/tmp/sysinfo/" ] || mkdir -p "/tmp/sysinfo/"
+	echo "$name" > /tmp/sysinfo/board_name
+	echo "unknown" > /tmp/sysinfo/model
+}
+
+boot_hook_add preinit_main do_sysinfo_orion