staging: unisys: Wire up proper device attr for bus

This patch moves the attributes to underneath the bus device correctly.
This will help remove a bunch of cruft from the code and let the kernel
infrastructure manage the sysfs files instead of the driver.

After the move remove all the leftover code.
Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>