CHROMIUM: config: disable rfkill

CHROMIUM: config: disable rfkill

We don't use rfkill in ChromeOS.

The rfkill_poll causes 1 wakeup / 5 seconds / per device.

BUG=chromium:227114
TEST=More details in the bug.
TEST=But I verified that wifi still works and verified that wakeups are reduced.

Change-Id: I92aa7fe4e0dbf806fb63ead7f3ba883f79a1a213
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/47808
Reviewed-by: Paul Stewart <pstew@chromium.org>
Reviewed-by: Sameer Nanda <snanda@chromium.org>