platform/chrome: chromeos_laptop - Add Dell Chromebook 11 touch

platform/chrome: chromeos_laptop - Add Dell Chromebook 11 touch

Add support for Dell Chromebook 11's touch device, which is the same
as falco/peppy on the same bus using the LynxPoint-LP I2C via the
i2c-designware-pci driver.

Based on these patches from the chromeos-3.8 kernel:
https://chromium-review.googlesource.com/#/c/65320/
https://chromium-review.googlesource.com/#/c/174664/

Signed-off-by: Mohammed Habibulla <moch@chromium.org>
Signed-off-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Olof Johansson <olof@lixom.net>