ARM: Exynos4: ADC: Universal_C210: Enable LDO4 power line for ADC measurement

ARM: Exynos4: ADC: Universal_C210: Enable LDO4 power line for ADC measurement

This patch enables LDO4 power line for preparing proper voltages to be
measured by ADC converter.
This measurement is used for determination of target board HW revision.

Test HW:
Universal_C210 (Exynos4210) rev. 0.0

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Minkyu Kang <mk7.kang@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>