staging: unisys: remove driver version from struct visor_driver

This patch removes the all instances of the driver version from
struct visor_driver. This includes removing version, vertag
(a human readable version string of the driver version) and
version_attr from struct visor_driver. This resulted in removing the
bus attributes and driver attributes which only contained the driver
version. The utsname function is used to replace the driver version
with the kernel version in bus_device_info_init().

Signed-off-by: Jon Frisch <jon.frisch@unisys.com>
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>