ARM: dts: qcom: Add power-controller device node for 8074 Krait CPUs

Each Krait CPU in the QCOM 8074/8974 SoC has an SAW power controller to
regulate the power to the cpu and aide the core in entering idle states.
Reference the SAW instance and associate the instance with the CPU core.

Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Kumar Gala <galak@codeaurora.org>
Signed-off-by: Olof Johansson <olof@lixom.net>