ARM: dts: exynos: simplify PMIC DVS pin configuration in Peach Pi

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>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20220111201722.327219-2-krzysztof.kozlowski@canonical.com