octeontx2-af: Handle non-contiguous CGX LMAC interfaces

For this, cgx_id(struct cgx) definition has been changed to
reflect cgx port id instead of device instance id.
Now cgx_id can be directly used as channel offset for NPC configuration.
Assumptions on contiguous cgx port ids has been removed from
nix_calibrate_x2p as well.

As a side effect, allocation of conversion tables that were based
on cgx count are changed to cgx port id max value.
Tables would return NULL for invalid cgx ports.

Signed-off-by: Linu Cherian <lcherian@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>