platform: msm_shared: add support to specify any DSI intf as primary

Current implementation assumes that for single DSI configurations, the
primary interface will always be selected as Interface_1 (DSI0).
However, it is possible that some board designs could use DSI1 for the
primary panel. Support this usecase by modifying all existing instances
of hardcoded interface base addresses to use a configurable base address
which is specified as part of panel header file.

Change-Id: I507cbe2986ed178e7fd0d8b5d4dcb3827f3935a3
7 files changed