staging: unisys: include: remove unused fields from struct visor_driver

The build_date and build_time fields are not used, and have been removed.

Signed-off-by: Tim Sell <Timothy.Sell@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>