Set and get mc index for rtl8367d family chips
Co-authored-by: Serge Vasilugin <vasilugin@yandex.ru>
Signed-off-by: Mieczyslaw Nalewaj <namiltd@yahoo.com>
Link: https://github.com/openwrt/openwrt/pull/14804
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>