ARM: dts: Unify voltage regulator style in exynos4412-odroid

Use 'ldoN_reg: LDON' syntax and drop the deprecated
'regulator-compatible' property.

Signed-off-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>