drivers: Fix htmldocs warnings with bus_find_next_device()

Document the parameters for bus_find_next_device() to avoid
htmldocs build warnings as reported below :

include/linux/device.h:236: warning: Function parameter or member 'bus' not described in 'bus_find_next_device'
include/linux/device.h:236: warning: Function parameter or member 'cur' not described in 'bus_find_next_device'
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20190801102026.27312-3-suzuki.poulose@arm.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/device.h

@@ -229,6 +229,8 @@ static inline struct device *bus_find_device_by_devt(struct bus_type *bus,
 /**
  * bus_find_next_device - Find the next device after a given device in a
  * given bus.
+ * @bus: bus type
+ * @cur: device to begin the search with.
  */
 static inline struct device *
 bus_find_next_device(struct bus_type *bus,struct device *cur)