Add support for interrupt moderation for ocrdma device.  Thresholds
for high interrupt rates are static values derived based on experimental
results.
Signed-off-by: NMitesh Ahuja <mitesh.ahuja@emulex.com>
Signed-off-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NSelvin Xavier <selvin.xavier@emulex.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>