drm/mediatek: config mipitx impedance with calibration data

Read calibration data from nvmem, and config mipitx impedance with
calibration data to make sure their impedance are 100ohm.

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>