SMDK5250: Add PMIC voltage settings

This patch adds required pmic voltage settings for SMDK5250.

Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Rajeshwari Shinde <rajeshwari.s@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>