fix(misra): fix remaining coverity misra issue

Change-Id: Ic55c92b17fb8e91fc1bacb5ccb0da76d7c96216f
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
diff --git a/lib/attestation/include/attestation_token.h b/lib/attestation/include/attestation_token.h
index bcc7ce8..c49946b 100644
--- a/lib/attestation/include/attestation_token.h
+++ b/lib/attestation/include/attestation_token.h
@@ -223,7 +223,7 @@
  */
 enum attest_token_err_t attest_token_ctx_init(struct token_sign_cntxt *token_ctx,
 			   unsigned char *heap_buf,
-			   unsigned int heap_buf_len,
+			   unsigned long heap_buf_len,
 			   uintptr_t cookie);
 
 /*