ARM: dts: exynos: Disable unused PMIC regulators on Exynos5422 Odroid boards

Disable unused PMIC regulators on Exynos5422 Odroid boards to reduce
energy used. According to schematics:
1. LDO12, LDO16 and LDO24 are not connected,
2. LDO26 is not used on Odroid HC1.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>