ARM: dts: exynos: remove deprecated unit address for LPDDR3 timings on Odroid

Passing maximum frequency of LPDDR3 memory timings as unit address was
deprecated in favor of 'max-freq' property.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20220206135918.211990-1-krzysztof.kozlowski@canonical.com