arm64: dts: rockchip: Drop edgeble-neu6b dcdc-reg4 regulator-init-microvolt

The 'regulator-init-microvolt' property is not currently supported by
any driver, it was simply carried on from downstream kernels.

rk3588-edgeble-neu6b-io.dtb: pmic@0: regulators:dcdc-reg4: Unevaluated properties are not allowed ('regulator-init-microvolt' was unexpected)

Remove the invalid property.

Signed-off-by: Jagan Teki <jagan@edgeble.ai>
Link: https://lore.kernel.org/r/20231125190522.87607-2-jagan@edgeble.ai


Signed-off-by: Heiko Stuebner <heiko@sntech.de>