dt-bindings: arm: qcom: Add zombie

Add entries in the device tree binding for sc7280-zombie.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Owen Yang <ecs.taipeikernel@gmail.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221205133603.v15.1.Idfcba5344b7995b44b7fa2e20f1aa4351defeca6@changeid