ARM: EXYNOS4: Update config file of NURI to enable RTC

This patch update config file of NURI board to enable RTC

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>