reset: implement a reset test

This adds a sandbox reset implementation (provider), a test client
device, instantiates them both from Sandbox's DT, and adds a DM test
that excercises everything.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>

arch/sandbox/include/asm/reset.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef __SANDBOX_RESET_H
+#define __SANDBOX_RESET_H
+
+#include <common.h>
+
+struct udevice;
+
+int sandbox_reset_query(struct udevice *dev, unsigned long id);
+
+int sandbox_reset_test_get(struct udevice *dev);
+int sandbox_reset_test_assert(struct udevice *dev);
+int sandbox_reset_test_deassert(struct udevice *dev);
+int sandbox_reset_test_free(struct udevice *dev);
+
+#endif