clk: samsung: Remove obsolete code for Exynos4412 ISP clocks

Exynos4412 ISP clock are provided by separate Exynos4412 ISP clock
driver, so support for them in Exynos4-clk driver can be removed.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sylwester Nawrocki <snawrocki@kernel.org>