commonlib/clamp.h: Relicense file to be BSD-compatible

I added this header in commit a6c8b4becbd12fe6043557ca1e398c1a7c691007
(nb/intel/sandybridge: Rewrite get_FRQ). Relicense it as "BSD-3-Clause
OR GPL-2.0-or-later" and move it into the BSD-licensed commonlib part.

Change-Id: I89ebdcdf8d06e78e624e37a443696981b3b17b7d
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66711
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/northbridge/intel/sandybridge/raminit_native.c b/src/northbridge/intel/sandybridge/raminit_native.c
index ca26628..7141116 100644
--- a/src/northbridge/intel/sandybridge/raminit_native.c
+++ b/src/northbridge/intel/sandybridge/raminit_native.c
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
-#include <commonlib/clamp.h>
+#include <commonlib/bsd/clamp.h>
 #include <console/console.h>
 #include <console/usb.h>
 #include <cpu/intel/model_206ax/model_206ax.h>