ARM: dts: Add sleep mode of regulator for exynos3250-rinato

This patch adds sleep mode of regulator for exynos3250-rinato board
to optimize power-consumption in sleep state.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>