ARM: dts: rockchip: Use the correct regulator properties on rv1108-elgin

The following properties:

- regulator-state-enabled
- regulator-state-disabled
- regulator-state-uv

are not valid ones as per
Documentation/devicetree/bindings/regulator/regulator.txt

Fix it by using the correct properties as per the dt bindings.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>