arm64: dts: renesas: r8a7796: move nodes which have no reg property out of bus

Move pmu_a5[73], timer and thermal-zones nodes from soc node to root node.
The nodes that have been moved do not have any register properties and thus
shouldn't be placed on the bus.

This problem is flagged by the compiler as follows:
$ make
...
  DTC     arch/arm64/boot/dts/renesas/r8a7796-salvator-x.dtb
...
arch/arm64/boot/dts/renesas/r8a7796-salvator-x.dtb: Warning (simple_bus_reg): Node /soc/timer missing or empty reg/ranges property
arch/arm64/boot/dts/renesas/r8a7796-salvator-x.dtb: Warning (simple_bus_reg): Node /soc/pmu_a57 missing or empty reg/ranges property
arch/arm64/boot/dts/renesas/r8a7796-salvator-x.dtb: Warning (simple_bus_reg): Node /soc/pmu_a53 missing or empty reg/ranges property
arch/arm64/boot/dts/renesas/r8a7796-salvator-x.dtb: Warning (simple_bus_reg): Node /soc/thermal-zones missing or empty reg/ranges property
...
  DTC     arch/arm64/boot/dts/renesas/r8a7796-m3ulcb.dtb
...
arch/arm64/boot/dts/renesas/r8a7796-m3ulcb.dtb: Warning (simple_bus_reg): Node /soc/timer missing or empty reg/ranges property
arch/arm64/boot/dts/renesas/r8a7796-m3ulcb.dtb: Warning (simple_bus_reg): Node /soc/pmu_a57 missing or empty reg/ranges property
arch/arm64/boot/dts/renesas/r8a7796-m3ulcb.dtb: Warning (simple_bus_reg): Node /soc/pmu_a53 missing or empty reg/ranges property
arch/arm64/boot/dts/renesas/r8a7796-m3ulcb.dtb: Warning (simple_bus_reg): Node /soc/thermal-zones missing or empty reg/ranges property
...
  DTC     arch/arm64/boot/dts/renesas/r8a7796-m3ulcb-kf.dtb
...
arch/arm64/boot/dts/renesas/r8a7796-m3ulcb-kf.dtb: Warning (simple_bus_reg): Node /soc/timer missing or empty reg/ranges property
arch/arm64/boot/dts/renesas/r8a7796-m3ulcb-kf.dtb: Warning (simple_bus_reg): Node /soc/pmu_a57 missing or empty reg/ranges property
arch/arm64/boot/dts/renesas/r8a7796-m3ulcb-kf.dtb: Warning (simple_bus_reg): Node /soc/pmu_a53 missing or empty reg/ranges property
arch/arm64/boot/dts/renesas/r8a7796-m3ulcb-kf.dtb: Warning (simple_bus_reg): Node /soc/thermal-zones missing or empty reg/ranges property
...
  DTC     arch/arm64/boot/dts/renesas/r8a7796-salvator-xs.dtb
...
arch/arm64/boot/dts/renesas/r8a7796-salvator-xs.dtb: Warning (simple_bus_reg): Node /soc/timer missing or empty reg/ranges property
arch/arm64/boot/dts/renesas/r8a7796-salvator-xs.dtb: Warning (simple_bus_reg): Node /soc/pmu_a57 missing or empty reg/ranges property
arch/arm64/boot/dts/renesas/r8a7796-salvator-xs.dtb: Warning (simple_bus_reg): Node /soc/pmu_a53 missing or empty reg/ranges property
arch/arm64/boot/dts/renesas/r8a7796-salvator-xs.dtb: Warning (simple_bus_reg): Node /soc/thermal-zones missing or empty reg/ranges property
...

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>