dt-bindings: mediatek: add description for postmask

add description for postmask
postmask is used control round corner for display frame

Signed-off-by: Yongqiang Niu <yongqiang.niu@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
This commit is contained in:
Yongqiang Niu 2021-01-11 15:43:37 +08:00 • committed by Chun-Kuang Hu
commit fb8b6c307c