staging: unisys: Move vbushelper.h contents to visorbus_private.h

The contents of vbushelper.h are now only used by visorbus, so it no longer
needs to be a general include file and it can be incorporated in the
visorbus private header.

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