powerpc/83xx: add DS1374 RTC support for the MPC837xE-MDS boards

The RTC is sitting on the I2C1 bus at address 0x68. RTC interrupt signal
is connected to the IPIC's EXT3 interrupt line.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/boot/dts/mpc8377_mds.dts

@@ -136,6 +136,13 @@ i2c@3000 {
 			interrupts = <14 0x8>;
 			interrupt-parent = <&ipic>;
 			dfsrr;
+
+			rtc@68 {
+				compatible = "dallas,ds1374";
+				reg = <0x68>;
+				interrupts = <19 0x8>;
+				interrupt-parent = <&ipic>;
+			};
 		};
 
 		i2c@3100 {

arch/powerpc/boot/dts/mpc8378_mds.dts

@@ -136,6 +136,13 @@ i2c@3000 {
 			interrupts = <14 0x8>;
 			interrupt-parent = <&ipic>;
 			dfsrr;
+
+			rtc@68 {
+				compatible = "dallas,ds1374";
+				reg = <0x68>;
+				interrupts = <19 0x8>;
+				interrupt-parent = <&ipic>;
+			};
 		};
 
 		i2c@3100 {

arch/powerpc/boot/dts/mpc8379_mds.dts

@@ -136,6 +136,13 @@ i2c@3000 {
 			interrupts = <14 0x8>;
 			interrupt-parent = <&ipic>;
 			dfsrr;
+
+			rtc@68 {
+				compatible = "dallas,ds1374";
+				reg = <0x68>;
+				interrupts = <19 0x8>;
+				interrupt-parent = <&ipic>;
+			};
 		};
 
 		i2c@3100 {