[i.MX8M]How to monitoring the temperature of thermal die in SOC

Thermal driver is a necessary driver for monitoring and protecting the SoC. The thermal
driver will monitor the SoC temperature in a certain frequency.
It defines two trip points: critical and passive. Cooling device will take actions to protect
the SoC according to the different trip points that SoC has reached:
• When reaching critical point, cooling device will shut down the system.
• When reaching passive point, cooling device will lower CPU frequency and notify
GPU/VPU to run at a lower frequency.
• When the temperature drops to 10 °C below passive point, cooling device will
release all the cooling actions.

Thermal driver has two parts:
• Thermal zone defines trip points and monitors the SoC's temperature.
• Cooling device takes the actions according to the different trip points.
The critical and passive points threshold are defined as follows:
• i.MX 6 and i.MX 7 platforms: drivers/thermal/imx_thermal.c
• i.MX 8QuadMax: arch/arm64/boot/dts/freescale/fsl-imx8qm.dtsi
• i.MX 8QuadXPlus: arch/arm64/boot/dts/freescale/fsl-imx8qxp.dtsi

• i.MX 8MQuad: arch/arm64/boot/dts/freescale/fsl-imx8mq.dtsi

We can cat the file to read the real-time thermal temperature,