sdm/hwc: Add support for concurrent writeback

Add support to:
-- Read CWB capability from driver
-- Capture 1 CWB frame in client provided buffer (LM/DSPP choice)
-- Capture and dump N CWB frames into a file (DSPP output)
-- Read writeback index from driver, rather than using rotator count
-- Move output frame dump API to base class + API clean-up
-- Use SDM format string in output file name, since some HAL formats
   don't support UBWC directly, and also to be compatible with
   BufferInfo.

Change-Id: Ic7ea5ae821695da1e04cf26bc47e134d974c3c88
CRs-fixed: 1001171
17 files changed