ARM: dts: msm: enable HDMI and DSI displays on 8996 auto CDP platform

MSM8996 Auto CDP platform changes to use DSI-HDMI bridge chip. This
change is to enable both native HDMI and one DSI-HDMI port for this
platform. And native HDMI is the primary display.

Change-Id: I1639753a914682050d974edebeec0f9141a3787d
Signed-off-by: Jin Li <jinl@codeaurora.org>