nfp: add support for coalesce adaptive feature

Use dynamic interrupt moderation library to implement coalesce
adaptive feature for nfp driver.

Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Yu Xiao <yu.xiao@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>