[PORT FROM R2] atmel_mxt224: change idle acquisition interval back to 32ms

[PORT FROM R2] atmel_mxt224: change idle acquisition interval back to 32ms

BZ: 20572

Idle acquisition interval can impact power consumption for idle-display-on
case on our platform. The 25mW interval consumes ~14mW, while 32ms
consumes ~7mW and can still maintain the user experience, no touch delay
from idle to active.

Change-Id: I5277eb4d9a00f10ba15960a080831d9753f39dc8
Orig-Change-Id: Ic0b60816bd710b8c80e2dc6f1cf5e538fcda7f49
Signed-off-by: Hong Liu <hong.liu@intel.com>
Reviewed-on: http://android.intel.com:8080/34461
Reviewed-by: Du, Alek <alek.du@intel.com>
Tested-by: Wang, Zhifeng <zhifeng.wang@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>