arm64: dts: renesas: r8a779g0: Add thermal nodes

Add device nodes for the Thermal Sensor/Chip Internal Voltage
Monitor/Core Voltage Monitor (THS/CIVM/CVM) and the various thermal
zones on the Renesas R-Car V4H (R8A779G0) SoC.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/b92a1a28afb9f75f24f0137af9f77e95d7ebaec3.1675959327.git.geert+renesas@glider.be