staging: kpc2000: export more device attributes via sysfs.

Added more read-only device attributes in order to expose all the
information about the hardware which is available by calling read() or
ioct() on the misc device associated with it.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>