ARM: dts: Use define for s3c-rtc clock id for exynos3250-monk

Use a define instead of raw number as a ID for "rtc_src" clock.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Kukjin Kim <kgene@kernel.org>

arch/arm/boot/dts/exynos3250-monk.dts

@@ -16,6 +16,7 @@
 #include "exynos3250.dtsi"
 #include <dt-bindings/input/input.h>
 #include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/clock/samsung,s2mps11.h>
 
 / {
 	model = "Samsung Monk board";
@@ -432,7 +433,7 @@ &tmu {
 };
 
 &rtc {
-	clocks = <&cmu CLK_RTC>, <&s2mps14_osc 0>;
+	clocks = <&cmu CLK_RTC>, <&s2mps14_osc S2MPS11_CLK_AP>;
 	clock-names = "rtc", "rtc_src";
 	status = "okay";
 };