Allow SMP affinity to be changeable by disabling managed interrupts.

On distributions where the driver is enabled for multi-queue support the
driver utilizes kernel managed interrupts, which automatically distributes
interrupts to all available CPUs and assigns SMP affinity.

On most distributions, the affinity can not be changed by the user.

This change will allow managed interrupts to be disabled by the user via a
module parameter while still allowing multi-queue support to function
properly.

Use the module parameter disable_managed_interrupts=1

Link: https://lore.kernel.org/r/165730606638.177165.12846020942931640329.stgit@brunhildaReviewed-by: Scott Benesh <scott.benesh@microchip.com>
Reviewed-by: Scott Teel <scott.teel@microchip.com>
Reviewed-by: Kevin Barnett <kevin.barnett@microchip.com>
Signed-off-by: Mike McGowen <Mike.McGowen@microchip.com>
Signed-off-by: Don Brace <don.brace@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>