arm64: dts: ti: j7200: Add VTM node

VTM stands for Voltage Thermal Management. Add the thermal zones.
Three sensors mapping to 3 thermal zones. MCU, MPU & Main domains
respectively.

Signed-off-by: Keerthy <j-keerthy@ti.com>
[bb@ti.com: rebased on v6.3-rc1]
Signed-off-by: Bryan Brattlof <bb@ti.com>
Link: https://lore.kernel.org/r/20230405215328.3755561-7-bb@ti.com


Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>