net/mlx5e: Refactor ptys2ethtool_adver_link()

net/mlx5e: Refactor ptys2ethtool_adver_link()

The function ptys2ethtool_adver_link() contains duplicated code that
is found in mlx5e_ethtool_get_speed_arr().

To eliminate this redundancy, we update mlx5e_ethtool_get_speed_arr()
to select the appropriate table based on the ext argument passed by
the caller, rather than querying the supported mode locally.

This allows us to replace the current logic in ptys2ethtool_adver_link()
with a call to mlx5e_ethtool_get_speed_arr().

This adjustment aligns with the ptys2ethtool_supported_link() function
and prepares for an upcoming patch that reduces code duplication.

Signed-off-by: Shahar Shitrit <shshitrit@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20250219114112.403808-3-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>