fix Alstec, Eltex pon/rg, qsw8200, dlink get_inventory
See merge request !3068 (merged)
(cherry picked from commit bda8a199)
63115040 fix Alstec, Eltex pon, qsw8200 get_inventory 641eb416 add eltex, dlink 4f3e2e2c fix lint bcc61dd7 fix qtech qsw get_inventory