Add a module_types variable to the link_info struct to save the module
information from get_phy_capabilities. This information can be used to
determine which speeds the module supports.
Also add a new function update_link_info which updates the module_types
parameter and then calls get_link_info. This function should be called
in place of get_link_info so that the module_types variable stays
up-to-date with the rest of the link information.
Also rework the function get_link_status to allow caller to get all
return values in the call chain bubbled back to the source, which keeps
information about failures from being lost.