net: thunderx: Assign affinity hints to vf's interrupts

This affinity hint can be used by user space irqbalance tool to set
preferred CPU mask for irqs registered by this VF. Irqbalance needs
to be in 'exact' mode to set irq affinity same as indicated by
affinity hint.

Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>