[PATCH V2] platform-driver-x86: ACPI EC Extra driver for Oaktrail

[Yin Kangkai]

Patch V2
Changes from V1:
  - remove wifi, bt, gps, wwan from /sys/devices/platform.
  - add some helper function for rfkill alloc and rfkill cleanup.
  - add MODULE_ALIAS.
  - add Documentation/ABI/testing/sysfs-platform-intel-oaktrail
  - various other minor changes.
  - bump driver version from 0.1 to 0.2

Thanks Corentin Chary and Joey Lee for the review.