dt-bindings: mfd: google,cros-ec: Add missing properties

dt-bindings: mfd: google,cros-ec: Add missing properties

Add common properties appearing in DTSes (controller-data,
wakeup-source) to partially fix dtbs_check warnings like:

  arch/arm/boot/dts/exynos5250-snow.dt.yaml: embedded-controller@1e:
    'keyboard-controller', 'wakeup-source' do not match any of the regexes: 'pinctrl-[0-9]+'

  arch/arm/boot/dts/exynos5800-peach-pi.dt.yaml: cros-ec@0:
    'controller-data', 'i2c-tunnel', 'keyboard-controller' do not match any of the regexes: 'pinctrl-[0-9]+'

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200903191407.12686-1-krzk@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>