dt-bindings: mediatek: add ovl_2l description for mt8183 display

Update device tree binding documention for the display subsystem for
Mediatek MT8183 SOCs

Signed-off-by: Yongqiang Niu <yongqiang.niu@mediatek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: CK Hu <ck.hu@mediatek.com>
1 file changed