powerpc/86xx: Add use of Epson RTX-8581 RTC to GE Fanuc SBC610 dts

Adding use of newly added Epson RTX-8581 real-time clock driver to GE
Fanuc SBC610's dts file and adding driver to default config.

Signed-off-by: Martyn Welch <martyn.welch@gefanuc.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/boot/dts/gef_sbc610.dts b/arch/powerpc/boot/dts/gef_sbc610.dts
index e48cfa7..c5d546a 100644
--- a/arch/powerpc/boot/dts/gef_sbc610.dts
+++ b/arch/powerpc/boot/dts/gef_sbc610.dts
@@ -119,6 +119,11 @@
 			interrupt-parent = <&mpic>;
 			dfsrr;
 
+			rtc@51 {
+				compatible = "epson,rx8581";
+				reg = <0x00000051>;
+			};
+
 			eti@6b {
 				compatible = "dallas,ds1682";
 				reg = <0x6b>;