ARM: dts: exynos: simplify PMIC DVS pin configuration in Odroid XU

The pin configuration for PMIC DVS (pmic-dvs-2 and pmic-dvs-3) are
exactly the same, so merge them.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20220111201426.326777-5-krzysztof.kozlowski@canonical.com