dt-bindings: display: mediatek: disp: split each block to individual yaml

1. Remove mediatek,dislpay.txt
2. Split each display function block to individual yaml file.

Signed-off-by: jason-jh.lin <jason-jh.lin@mediatek.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>