FROMGIT: driver core: Add fwnode_to_dev() to look up device from fwnode

It's often useful to look up a device that corresponds to a fwnode. So
add an API to do that irrespective of the bus on which the device has
been added to.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20190904211126.47518-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

(cherry-picked from commit 372a67c0c5
 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git driver-core-next)

Bug: 141703324
Change-Id: I68c36177da083bfb04e73c1b754e740f40faf284

include/linux/fwnode.h

@@ -17,6 +17,7 @@ struct device;
 struct fwnode_handle {
 	struct fwnode_handle *secondary;
 	const struct fwnode_operations *ops;
+	struct device *dev;
 };
 
 /**
@@ -123,5 +124,6 @@ struct fwnode_operations {
 		if (fwnode_has_op(fwnode, op))				\
 			(fwnode)->ops->op(fwnode, ## __VA_ARGS__);	\
 	} while (false)
+#define get_dev_from_fwnode(fwnode)	get_device((fwnode)->dev)
 
 #endif