include/uuid.h: Add missing include

uuid.h uses uint8_t which is provided by stdint.h.

BUG=b:153675915
TEST=Fixed my compiler error.

Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: Idbec40f444d9df7587b9066faac65499415dae6e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41803
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/include/uuid.h

@@ -4,6 +4,7 @@
 #define _UUID_H_
 
 #include <string.h>
+#include <stdint.h>
 
 #define UUID_LEN	16
 #define UUID_STRLEN	36