GFX-Display: support CTP command mode DSR.

GFX-Display: support CTP command mode DSR.

BZ: 29754

1. update code of DSR mode enter condition
2. for 0x36 memory tranfer direction , it does not every time
need to send, so clear it.
3. fix command mode shift issue ,which lead by 0x70184 mistake
4. improve debug read interface, considering command mode

Change-Id: I49065908b72870d742870ed63c16961c785880b9
Signed-off-by: Ke Ai <ke.ai@intel.com>
Reviewed-on: http://android.intel.com:8080/41720
Reviewed-by: Tong, BoX <box.tong@intel.com>
Tested-by: Tong, BoX <box.tong@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>