powerpc/dts: Standardize DTS status assignments from "ok" to "okay"

While the current kernel drivers/of/ code allows developers to be
sloppy and use a DTS status value of "ok", the current DTSpec 0.1
makes it clear that the proper spelling is "okay", so fix the small
number of PowerPC .dts files that do this.
Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

arch/powerpc/boot/dts/akebono.dts

@@ -40,7 +40,7 @@
 			d-cache-size = <32768>;
 			dcr-controller;
 			dcr-access-method = "native";
-			status = "ok";
+			status = "okay";
 		};
 		cpu@1 {
 			device_type = "cpu";

arch/powerpc/boot/dts/bluestone.dts

@@ -109,7 +109,7 @@
 
 	OCM: ocm@400040000 {
 		compatible = "ibm,ocm";
-		status = "ok";
+		status = "okay";
 		cell-index = <1>;
 		/* configured in U-Boot */
 		reg = <4 0x00040000 0x8000>; /* 32K */

arch/powerpc/boot/dts/currituck.dts

@@ -39,7 +39,7 @@
 			d-cache-size = <32768>;
 			dcr-controller;
 			dcr-access-method = "native";
-			status = "ok";
+			status = "okay";
 		};
 		cpu@1 {
 			device_type = "cpu";

arch/powerpc/boot/dts/iss4xx-mpic.dts

@@ -43,7 +43,7 @@
 			d-cache-size = <32768>;
 			dcr-controller;
 			dcr-access-method = "native";
-			status = "ok";
+			status = "okay";
 		};
 		cpu@1 {
 			device_type = "cpu";