soc: samsung: pm_domains: Deprecate support for clocks

Handling of special clock operations on power domain on/off sequences has
been moved to respective Exynos clock controller drivers, so there is no
need to keep the duplicated (and conflicting) code in Exynos power domain
driver. Mark clock related properties in Exynos power domain bindings as
deprecated. This change has no inpact on backwards-compatibility, as the
new drivers properly work with old DTBs (deprecated properties are
ignored).

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