ionic: improve irq numa locality

Spreading the interrupts across the CPU cores is good for load
balancing, but not necessarily as good when using a CPU/core
that is not part of the NUMA local CPU.  If it can be localized,
the kernel's cpumask_local_spread() service will pick a core
that is on the node close to the PCI device.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>