CHROMIUM: Input: atmel_mxt_ts : On Tpads, enable T42, disable T19 on suspend

CHROMIUM: Input: atmel_mxt_ts : On Tpads, enable T42, disable T19 on suspend

To work around an issue where an idle-suspended system may wake
unnecessarily when the lid is closed because the B panel comes close to
the trackpad, enable touch suppression (t42) when suspending. Also
disable T19, for the button, to allow the button to be pressed if
the case is flexed without the system waking.

Signed-off-by: Benson Leung <bleung@chromium.org>
BUG=chrome-os-partner:17336
TEST=1. Suspend the system with powerd_suspend with lid open.
2. Touch the touchpad. Make sure the system still wakes.
3. Suspend again with powerd_suspend
4. Close the lid. Ensure the system does not wake by observing the system
status light.

Change-Id: I858af27e65ce491c8eb99f5b8db13ea91f789f3e
Reviewed-on: https://gerrit.chromium.org/gerrit/41678
Reviewed-by: Puneet Kumar <puneetster@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Commit-Queue: Benson Leung <bleung@chromium.org>
Tested-by: Benson Leung <bleung@chromium.org>