drm/sde: set display h/v polarity according to panel info

The h/v polarity should always be set from the panel configuration.
For HDMI display, it's from the EDID information. For DSI display,
it's from the panel settings in the dtsi.

CRs-Fixed: 1085021
Change-Id: I3776603d7055e69eb2c8e5003ab83bc0483ab7c8
Signed-off-by: Jin Li <jinl@codeaurora.org>