clk: exynos4x12: add cpu clock configuration data and instantiate cpu clock

With the addition of the new Samsung specific cpu-clock type, the
arm clock can be represented as a cpu-clock type. Add the CPU clock
configuration data and instantiate the CPU clock type for Exynos4x12.

Based on the earlier work by Thomas Abraham.

Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Thomas Abraham <thomas.ab@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>