arm64: dts: imx8mq: enable the multi sensor TMU

Add the imx8mq TMU (Thermal management unit) nodes for CPU,
GPU, and VPU.

Signed-off-by: Angus Ainslie (Purism) <angus@akkea.ca>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>