Move elog_internal.h to commonlib/bsd/include

Move elog_internal.h to commonlib/bsd/include/bsd/.
And rename it from elog_internal.h to elog.h.

Since this file will be included from util/ it also converts the "uNN"
types into "uintNN_t" types.

The two defines that are not used by util/ are moved to
drivers/elog/elog.c, the only file that includes them.

Move also the function elog_verify_header() from drivers/elog/, to
commonlib/bsd/elog.c since this function will be called from util/
as well.

The rationale behind moving elog's defines & structs to
commonlib/bsd/include is to make them available to util/ tools and/or
payloads (should it be needed in the future).

The files that are being relicensed to BSD were coded by Duncan Laurie,
and he is Ok with the relicense.

BUG=b:172210863

Signed-off-by: Ricardo Quesada <ricardoq@google.com>
Change-Id: Ia1aefea705ddd417a1d9e978bb18ab6d9a60cad6
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56404
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

src/commonlib/bsd/elog.c

@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+
+#include <commonlib/bsd/elog.h>
+#include <stddef.h>
+
+/*
+ * verify and validate if header is a valid coreboot Event Log header.
+ * return CB_ERR if invalid, otherwise CB_SUCCESS.
+ */
+enum cb_err elog_verify_header(const struct elog_header *header)
+{
+	if (header == NULL)
+		return CB_ERR;
+
+	if (header->magic != ELOG_SIGNATURE)
+		return CB_ERR;
+
+	if (header->version != ELOG_VERSION)
+		return CB_ERR;
+
+	if (header->header_size != sizeof(*header))
+		return CB_ERR;
+
+	return CB_SUCCESS;
+}