ec/starlabs/merlin/kbl: Add required headers for dead_code_t

Signed-off-by: Sean Rhodes <sean@starlabs.systems>
Change-Id: Ia6c3ba80d5e6ac3d4fd8a935732ef7e32cf33998
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64718
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <gaumless@tutanota.com>

src/ec/starlabs/merlin/variants/kbl/ecdefs.h

@@ -1,5 +1,8 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
+#include <assert.h>
+#include <stdint.h>
+
 /*
  * EC communication interface for ITE Embedded Controller
  */