octeontx2-pf: cn10k: Initialise NIX context

On CN10K platform NIX RQ and SQ context structure got changed.
This patch uses new mbox message "NIX_CN10K_AQ_ENQ" for NIX
context initialization on CN10K platform.

This patch also updates the nix_rx_parse_s and nix_sqe_sg_s
structures to add packet steering bit feilds.

Signed-off-by: Geetha sowjanya <gakula@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>