include/bcd: move bcd code to commonlib/bsd/include

Move bcd2bin() / bin2bcd() functions to commonlib/bsd/include/

Also, the license is changed from GPL to BSD.
This is because it is needed from "utils" (see CL in the chain).

For reference bin2bcd() & bcd2bin() are very simple functions.
There are already BSD implementations, like these ones (just to
name a few):
https://chromium.googlesource.com/chromiumos/platform/mosys/+/refs/heads/main/include/lib/math.h#67
http://web.mit.edu/freebsd/head/sys/contrib/octeon-sdk/cvmx-cn3010-evb-hs5.c

BUG=b:172210863
TEST=make (everything compiled Ok).

Change-Id: If2eba82da35838799bcbcf38303de6bd53f7eb72
Signed-off-by: Ricardo Quesada <ricardoq@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56904
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/commonlib/bsd/include/commonlib/bsd/bcd.h

@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+
+#ifndef _BCD_H_
+#define _BCD_H_
+
+#include <stdint.h>
+
+static inline uint8_t bcd2bin(uint8_t val)
+{
+	return ((val >> 4) & 0xf) * 10 + (val & 0xf);
+}
+
+static inline uint8_t bin2bcd(uint8_t val)
+{
+	return ((val / 10) << 4) | (val % 10);
+}
+
+#endif /* _BCD_H_ */