[POWERPC] Rename device_is_compatible to of_device_is_compatible

for consistency with other Open Firmware interfaces (and Sparc).

This is just a straight replacement.

This leaves the compatibility define in place.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c
index 9eaefac..ec87106 100644
--- a/arch/powerpc/kernel/vio.c
+++ b/arch/powerpc/kernel/vio.c
@@ -117,7 +117,7 @@
 {
 	while (ids->type[0] != '\0') {
 		if ((strncmp(dev->type, ids->type, strlen(ids->type)) == 0) &&
-		    device_is_compatible(dev->dev.archdata.of_node,
+		    of_device_is_compatible(dev->dev.archdata.of_node,
 					 ids->compat))
 			return ids;
 		ids++;