USB: cxacru: export detailed device info through sysfs

When the device is polled for status there is a lot of useful status
information available that is ignored.  This patch stores the device info
array when the status is polled and adds sysfs files to the usb device to
allow userspace to query it.  Since the device updates its status
internally once a second the poll time is changed to this, and
round_jiffies_relative is used to avoid waking the cpu unnecessarily.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Cc: Duncan Sands <duncan.sands@free.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>