octeontx2-pf: mcs: Introduce MACSEC hardware offloading

This patch introduces the macsec offload feature to cn10k
PF netdev driver. The macsec offload ops like adding, deleting
and updating SecYs, SCs, SAs and stats are supported. XPN support
will be added in later patches. Some stats use same counter in hardware
which means based on the SecY mode the same counter represents different
stat. Hence when SecY mode/policy is changed then snapshot of current
stats are captured. Also there is no provision to specify the unique
flow-id/SCI per packet to hardware hence different mac address needs to
be set for macsec interfaces.

Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>