ppc/pnv: Add PnvChipClass handler to get reference to interrupt controller

ppc/pnv: Add PnvChipClass handler to get reference to interrupt controller

Existing code in XIVE2 assumes the chip to be a Power10 Chip.
Instead add a handler to get reference to the interrupt controller (XIVE)
for a given Power Chip.

Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Tested-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Tested-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Link: https://lore.kernel.org/r/20250925173049.891406-4-adityag@linux.ibm.com
Message-ID: <20250925173049.891406-4-adityag@linux.ibm.com>