cpufreq: dt: Remove support for Exynos4212 SoCs

Support for Exynos4212 SoCs has been removed by commit bca9085e
"ARM: dts: exynos: remove Exynos4212 support (dead code)", so there
is no need to keep remaining dead code related to this SoC version.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>