Driver core: Add accessor for device platform data

For consistency with driver data provide a dev_get_platdata() accessor
for reading the platform data from a device.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/linux/device.h b/include/linux/device.h
index c0bd230..3f33f17 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -494,6 +494,11 @@
 }
 extern void root_device_unregister(struct device *root);
 
+static inline void *dev_get_platdata(const struct device *dev)
+{
+	return dev->platform_data;
+}
+
 /*
  * Manual binding of a device to driver. See drivers/base/bus.c
  * for information on use.