arm64: defconfig: Enable ChromeOS EC drivers for supported Chromebooks.

Enable following drivers for merged devices:
- ChromeOS EC RTC driver.
- ChromeOS EC userspace interface.
- ChromeOS EC light and proximity sensors.
- ChromeOS EC Barometer Sensor driver.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>