ARM: dts: qcom: Add support for ASUS ZenWatch 2

Add support for this smartwatch, based on Snapdragon 400 SoC.

Currently supported functionality:
* Internal storage
* USB
* Charger
* Power button
* Vibration motor
* Bluetooth
* Wifi

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220226101939.1011551-2-luca@z3ntu.xyz