arch/x86: add missing license headers

These were mostly written as part of the coreboot project, so get
the standard coreboot license header.

memmove.c came from the linux kernel, so also gets the standard
coreboot v2 license header, but gets the added attribution that it
was derived from the linux kernel.  Unlike many coreboot files,
this file may not be re-licensed as GPL V3.

Change-Id: I1fdc26b543e059f7a42d4b886f7222f4c74b959d
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/12916
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/src/arch/x86/cpu.c b/src/arch/x86/cpu.c
index 52b5681..0d670aa 100644
--- a/src/arch/x86/cpu.c
+++ b/src/arch/x86/cpu.c
@@ -1,3 +1,16 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
 #include <console/console.h>
 #include <cpu/cpu.h>
 #include <arch/io.h>