arm64: dts: qcom: pm8998: Add spmi-temp-alarm node

This adds the spmi-temp-alarm node to pm8998 based on the examples in the
bindings.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>