arm64: dts: qcom: msm8916-wingtech-wt88047: Add notification LED

The Xiaomi Redmi 2 has a notification LED connected to an Awinic
AW2013 controller, add it to the device tree.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20210712133735.318250-3-stephan@gerhold.net


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>