arm64: dts: exynos: drop clock-frequency from CPU nodes in TM2

The CPU frequencies are determined by OPP table, so drop the
'clock-frequency' property.  It is not parsed by any driver.

Link: https://lore.kernel.org/r/20221204113839.151816-2-krzysztof.kozlowski@linaro.org


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>