tests: update CMocka to stable-1.1

CMocka stable-1.1 has some convenience bugfixes like vprint buffer
increase or leftover values log fix (funtion names display correctly
now.

Signed-off-by: Jakub Czapiga <jacz@semihalf.com>
Change-Id: I20ebd15324a21c17cccd2976ae9c3f86b040426d
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63636
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

tests/lib/b64_decode-test.c

@@ -35,7 +35,7 @@ static void test_b64_decode(void **state)
 		res = b64_decode((uint8_t *)messages[i].enc, strlen(messages[i].enc), decoded);
 
 		assert_int_equal(res, (strlen(messages[i].dec)));
-		assert_string_equal(decoded, messages[i].dec);
+		assert_string_equal((const char *)decoded, messages[i].dec);
 
 		free(decoded);
 	}