x86: crownbay: Enable DM RTC support

Add a RTC node in the device tree to enable DM RTC support.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/dts/crownbay.dts b/arch/x86/dts/crownbay.dts
index 1ec90cd..87ed0f4 100644
--- a/arch/x86/dts/crownbay.dts
+++ b/arch/x86/dts/crownbay.dts
@@ -10,6 +10,7 @@
 
 /include/ "skeleton.dtsi"
 /include/ "serial.dtsi"
+/include/ "rtc.dtsi"
 
 / {
 	model = "Intel Crown Bay";
diff --git a/arch/x86/dts/rtc.dtsi b/arch/x86/dts/rtc.dtsi
new file mode 100644
index 0000000..93dacd7
--- /dev/null
+++ b/arch/x86/dts/rtc.dtsi
@@ -0,0 +1,6 @@
+/ {
+	rtc {
+		compatible = "motorola,mc146818";
+		reg = <0x70 2>;
+	};
+};