net/mlx5e: Support FEC settings for 100G/lane modes

This consists of:
1. Expose the 100G/lane capability bit in the PCAM reg.
2. Expose the per link mode FEC capability masks in the PPLM reg.
3. Set the overrides according to ethtool parameters.
FEC for new modes is set if and only if the PCAM 100G/lane capability is
advertised and the capability mask for a given link mode reports that it
can accept the requested FEC mode.

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/20240404173357.123307-3-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>