arm64: dts: qcom: msm8996: move clock-frequency from PN547 NFC to I2C bus

Although the early NXP NCI NFC bindings required the clock-frequency
property, it was never used by the driver and it is actually a property
of I2C bus, not I2C slave.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211011073143.32645-1-krzysztof.kozlowski@canonical.com