lib/hardwaremain: add missing types.h include

The u8 type is used in the file, but neither stdint.h not types.h was
included in the file.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Ifd67aff9eba01f9618004c869f1473217b3aeae4
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58075
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/lib/hardwaremain.c

@@ -23,6 +23,7 @@
 #include <thread.h>
 #include <timer.h>
 #include <timestamp.h>
+#include <types.h>
 #include <vendorcode/google/chromeos/gnvs.h>
 #include <version.h>