util/amdfwtool: portability fixes for FreeBSD

Add the stdint.h header, and drop the GLIBC section from amdfwtool.h to build this tool on FreeBSD as well as Linux.

Signed-off-by: Idwer Vollering <vidwer@gmail.com>
Change-Id: I295fd308b0f5e2902931f02c9455823a614976de
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48977
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

util/amdfwtool/data_parse.c

@@ -2,6 +2,7 @@
 #include <regex.h>
 #include <string.h>
 #include <stdlib.h>
+#include <stdint.h>
 
 #include "amdfwtool.h"