The compatible string isl,isl12022 is typo, it should be isil,isl12022.
Fix below CHECK_DTBS warning:
arch/arm/boot/dts/nxp/imx/imx6dl-ts7970.dtb: /soc/bus@2100000/i2c@21a0000/rtc@6f: failed to match any schema with compatible: ['isl,isl12022']
Signed-off-by: Frank Li <Frank.Li@nxp.com> Reviewed-by: Peng Fan <peng.fan@nxp.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>