s390: doc: detailed specifications for AP virtualization

s390: doc: detailed specifications for AP virtualization

This patch provides documentation describing the AP architecture and
design concepts behind the virtualization of AP devices. It also
includes an example of how to configure AP devices for exclusive
use of KVM guests.

Signed-off-by: Tony Krowiak <[email protected]>
Reviewed-by: Pierre Morel <[email protected]>
Tested-by: Pierre Morel <[email protected]>
Tested-by: Christian Borntraeger <[email protected]>
Message-Id: <20181010170309[email protected]>
Signed-off-by: Cornelia Huck <[email protected]>