Input: atmel_mxt_ts - do not pass suspend mode in platform data

The way we are supposed to put controller to sleep and wake it up does not
depend on the platform, but rather on controller itself, so we want to get
rid of suspend mode in platform data (and eventually get rid of platform
data completely). Unfortunately some early chromebooks (the original Pixel,
Acer C720) were shipped with config that requires manually re-enabling
touch reporting in T9. We will sort it out, but in the meantime let's
switch to a simple DMI quirk.

We'll keep pdata->suspend_mode for now and remove it when we rework
chromeos-laptop driver.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>