board: lx2160aqds: implement board_fit_config_name_match

In case CONFIG_DM_ETH and CONFIG_MULTI_DTB_FIT are enabled implement the
board_fit_config_name_match() function in order to choose the
appropriate DTS for the current SERDES protocol configuration.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Razvan Ionut Cirjan <razvanionut.cirjan@nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>