msm: mdss: abstract the dsi command utility API

The dsi command parsing and construction functionalities
are hardware independent.  This is to abstract these
utility API, so that it can be shared with different versions
of  dsi host controllers.

Change-Id: I8481d9fd21e5eacc4542c72c064fa37d7fd3a11b
Signed-off-by: Xiaoming Zhou <zhoux@codeaurora.org>

Conflicts:
	drivers/video/msm/mdss/mdss_dsi.h
	drivers/video/msm/mdss/mdss_dsi_cmd.c
msm: mdss: Add error handling support for DCS command APIs

Currently there is no error handling done for DSI DCS command
APIs like mdss_dsi_cmdlist_put. So for ESD thread use cases,
the caller functions of these DCS command APIs do not have error
propagated if the panel read/write commands fail. Hence add support
for error handling for these functions.

Change-Id: I0e558fd32fbfd8ae247b60c92fa2756159c3d3c6
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>