x86: add preinit hook to reload microcode

Signed-off-by: Zoltan HERPAI <wigyori@uid0.hu>

target/linux/x86/base-files/lib/preinit/02_load_x86_ucode

@@ -0,0 +1,10 @@
+#!/bin/sh
+# Copyright (C) 2018 OpenWrt.org
+
+do_load_x86_ucode() {
+	if [ -e "/sys/devices/system/cpu/microcode/reload" ]; then
+		echo 1 > /sys/devices/system/cpu/microcode/reload
+	fi
+}
+
+boot_hook_add preinit_main do_load_x86_ucode