x86: Move microcode code to a common location

This code is used on several Intel CPUs. Move it into a common location.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/include/asm/microcode.h

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2015 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __ASM_ARCH_MICROCODE_H
+#define __ASM_ARCH_MICROCODE_H
+
+#ifndef __ASSEMBLY__
+
+/**
+ * microcode_update_intel() - Apply microcode updates
+ *
+ * Applies any microcode updates in the device tree.
+ *
+ * @return 0 if OK, -EEXIST if the updates were already applied, -ENOENT if
+ * not updates were found, -EINVAL if an update was invalid
+ */
+int microcode_update_intel(void);
+#endif /* __ASSEMBLY__ */
+
+#endif