test: Add framework to test hush behavior

Introduce a new subcommand to ut: ut hush.
For the moment, this command does nothing, future commits will add tests which
will be run on command call.

Note that CONFIG_HUSH_PARSER must be defined to compile this new subcommand.

Signed-off-by: Francis Laniel <francis.laniel@amarulasolutions.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/test/hush.h b/include/test/hush.h
new file mode 100644
index 0000000..cca6654
--- /dev/null
+++ b/include/test/hush.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * (C) Copyright 2021
+ * Francis Laniel, Amarula Solutions, francis.laniel@amarulasolutions.com
+ */
+
+#ifndef __TEST_HUSH_H__
+#define __TEST_HUSH_H__
+
+#include <test/test.h>
+
+/* Declare a new environment test */
+#define HUSH_TEST(_name, _flags)	UNIT_TEST(_name, _flags, hush_test)
+
+#endif /* __TEST_HUSH_H__ */