drm: msm: dsi-staging: add support for DSI controller v2.0.0

Add a separate DSI controller h/w driver to support DSI
controller v2.0.0. This includes reorganizing the DSI controller
programming sequence which is common between DSI v1.4.0 and
DSI v2.0.0 to a common DSI h/w driver file.

CRs-Fixed: 2008002
Change-Id: I6e2821b6874924c8fbaca888f940e8ad34ee90ec
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>
Signed-off-by: Shashank Babu Chinta Venkata <sbchin@codeaurora.org>