arm64: dts: colibri-imx8x: Set thermal thresholds

Set critical/alert thermal thresholds for all relevant SOC
temperature trips to the IT value (max T_junction 105 degree
Celsius) in accordance with the IT grade of the SOM.

Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>