Driver core: add bus_find_device_by_name function

The driver core, and some other parts of the kernel just want to find a
device based on a name for a specific bus.  Give them a simple wrapper
to prevent them from having to always roll their own.

This will be used in the PPC patch later in this series.

Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/linux/device.h b/include/linux/device.h
index 1880208..db375be 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -84,6 +84,9 @@
 struct device *bus_find_device(struct bus_type *bus, struct device *start,
 			       void *data,
 			       int (*match)(struct device *dev, void *data));
+struct device *bus_find_device_by_name(struct bus_type *bus,
+				       struct device *start,
+				       const char *name);
 
 int __must_check bus_for_each_drv(struct bus_type *bus,
 				  struct device_driver *start, void *data,