drm/rockchip: cdn-dp: Correct PHY register address

Correct some DP register address for PHY Configuration according to
latest datasheet.

Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1488940077-22297-3-git-send-email-zyw@rock-chips.com