octeontx2-af: Add FLR interrupt handler

RVU admin function (AF) has all the priviliges to cleanup
HW state when VFIO triggers a PCIe function level reset (FLR)
due to either reset or a VM crash. FLR for RVU PF1-PFn will
trigger an IRQ to AF.

This patch enables all RVU PF's FLR interrupts and registers a
handler. Upon receiving an interrupt, a workqueue is scheduled
to cleanup all hardware blocks being used by the PF which
received the FLR.

Signed-off-by: Geetha sowjanya <gakula@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>