ARM: dts: exynos: add USB DWC3 supplies to ArndaleOcta

Add required voltage regulators for USB DWC3 block on Exynos5420
ArndaleOcta board.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20220123111644.25540-7-krzysztof.kozlowski@canonical.com