Currently, when user space queries the link's parameters, as speed and
duplex, each parameter is passed from the driver to ethtool.

Instead, pass the link mode bit in use.
In Spectrum-1, simply pass the bit that is set to '1' from PTYS register.
In Spectrum-2, pass the first link mode bit in the mask of the used
link mode.
Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>