soc: samsung: exynos-asv: don't defer early on not-supported SoCs

Check if the SoC is really supported before gathering the needed
resources. This fixes endless deferred probe on some SoCs other than
Exynos5422 (like Exynos5410).

Fixes: 5ea42859 ("soc: samsung: Add Exynos Adaptive Supply Voltage driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Link: https://lore.kernel.org/r/20201207190517.262051-2-krzk@kernel.org


Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>