Add firmware API for updating RSS hash configuration and key. Move
RSS hash configuration from cxgb4_write_rss() to a separate function
cxgbe_write_rss_conf().
Also, rename cxgb4_write_rss() to cxgbe_write_rss() for consistency.
Original work by Surendra Mobiya <surendra@chelsio.com>
Signed-off-by: Kumar Sanghvi <kumaras@chelsio.com>
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>