ARM: dts: Add CPU OPP properties for exynos542x/5800

For Exynos542x/5800 platforms, add CPU operating points
for migrating from Exynos specific cpufreq driver to using
generic cpufreq driver.

Changes by Bartlomiej:
- split Exynos5420 support from the original patch
- merged Exynos5422 fixes from Ben

Changes by Ben Gamari:
- Port to operating-points-v2

Cc: Doug Anderson <dianders@chromium.org>
Cc: Javier Martinez Canillas <javier@osg.samsung.com>
Cc: Andreas Faerber <afaerber@suse.de>
Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
Signed-off-by: Ben Gamari <ben@smart-cactus.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>