USB: add driver for Meywa-Denki & Kayac YUREX

Meywa-Denki/Kayac YUREX is a leg-shakes sensor device.
See http://bbu.kayac.com/en/about/

 for further information.
This driver support read/write the leg-shakes counter in the device
via a device file /dev/yurex[0-9]*.

[minor coding style cleanups fixed by gregkh]

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>