vboot: add missing assert.h include

BUG=none
TEST=make
BRANCH=none

Signed-off-by: David Benjamin <davidben@chromium.org>
Change-Id: I4193d01bf9e65aff1567d4d00ae38811b61ad4c0
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2252761
Commit-Queue: Joel Kitching <kitching@chromium.org>
Reviewed-by: Joel Kitching <kitching@chromium.org>
diff --git a/firmware/stub/tpm_lite_stub.c b/firmware/stub/tpm_lite_stub.c
index 7d3e5d2..1f31c69 100644
--- a/firmware/stub/tpm_lite_stub.c
+++ b/firmware/stub/tpm_lite_stub.c
@@ -6,6 +6,7 @@
  * equivalents.
  */
 
+#include <assert.h>
 #include <stdint.h>
 #include <errno.h>
 #include <fcntl.h>