soc: samsung: pmu: Add dummy support for Exynos5433 SoC

Add compatible for Exynos5433 SoC, so the driver will bind and let other
drivers to use PMU regmap.

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