The ARM PMU and ARM architected timer nodes are part of ARM CPU design
therefore they should not be inside the soc node.  This also fixes DTC
W=1 warnings like:

    arch/arm64/boot/dts/exynos/exynos7.dtsi:472.11-480.5:
        Warning (simple_bus_reg): /soc/arm-pmu: missing or empty reg/ranges property
    arch/arm64/boot/dts/exynos/exynos7.dtsi:482.9-492.5:
        Warning (simple_bus_reg): /soc/timer: missing or empty reg/ranges property
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>