ppc/xive: Make XIVE generate the proper interrupt types

ppc/xive: Make XIVE generate the proper interrupt types

It should be generic Hypervisor Virtualization interrupts for HV
directed rings and traditional External Interrupts for the OS directed
ring.

Don't generate anything for the user ring as it isn't actually
supported.

Signed-off-by: Benjamin Herrenschmidt <[email protected]>
Signed-off-by: Cédric Le Goater <[email protected]>
Reviewed-by: David Gibson <[email protected]>
Message-Id: <20190606174409[email protected]>
Signed-off-by: David Gibson <[email protected]>