arm64: dts: imx8dxl: Pass fsl,imx8dxl-sc-thermal

arm64: dts: imx8dxl: Pass fsl,imx8dxl-sc-thermal

Pass 'fsl,imx8dxl-sc-thermal' to fix the following schema warning:

system-controller: thermal-sensor:compatible:0: 'fsl,imx8qxp-sc-thermal' was expected
	from schema $id: http://devicetree.org/schemas/firmware/fsl,scu.yaml#
system-controller: thermal-sensor:compatible: ['fsl,imx-sc-thermal'] is too short
	from schema $id: http://devicetree.org/schemas/firmware/fsl,scu.yaml#

Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>