staging: unisys: fix copyright statements

The copyright statements in the drivers need to be correct and
consistent; this patch fixes the year for all of them, and makes the
statement text cover just the GPL V2.

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>