Document the ti,am654-adc compatible already used in DTS:

  arch/arm64/boot/dts/ti/k3-am642-evm.dtb: adc: compatible:0: 'ti,am654-adc' is not one of ['ti,am3359-adc', 'ti,am4372-adc']
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220727155203.320929-1-krzysztof.kozlowski@linaro.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>