staging: unisys: Add s-Par visorhba

This driver create a host bus adapter device when s-Par sends a
device create message to create a storage adapter on the visorbus.
When the message is received by visorbus, the visorhba_probe function
is called and the hba device is created and managed by the visorhba
driver.

Signed-off-by: Erik Arfvidson <erik.arfvidson@unisys.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>