dm: cache: Create a uclass for cache

The cache UCLASS will be used for configure settings that can be found
in a CPU's L2 cache controller.

Add a uclass and a test for cache.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>

drivers/cache/cache-uclass.c

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Intel Corporation <www.intel.com>
+ */
+
+#include <common.h>
+#include <cache.h>
+#include <dm.h>
+
+int cache_get_info(struct udevice *dev, struct cache_info *info)
+{
+	struct cache_ops *ops = cache_get_ops(dev);
+
+	if (!ops->get_info)
+		return -ENOSYS;
+
+	return ops->get_info(dev, info);
+}
+
+UCLASS_DRIVER(cache) = {
+	.id		= UCLASS_CACHE,
+	.name		= "cache",
+	.post_bind	= dm_scan_fdt_dev,
+};