ARM: dts: fix wrong compatible string of Exynos3250 RTC dt node

Fix wrong compatible string of Exynos3250 RTC (Real-Time Clock) dt node.
The RTC of Exynos3250 must need additional source clock (XrtcXTI).
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/arm/boot/dts/exynos3250.dtsi

@@ -164,7 +164,7 @@
 		};
 
 		rtc: rtc@10070000 {
-			compatible = "samsung,s3c6410-rtc";
+			compatible = "samsung,exynos3250-rtc";
 			reg = <0x10070000 0x100>;
 			interrupts = <0 73 0>, <0 74 0>;
 			status = "disabled";