[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/of_device.c b/arch/powerpc/kernel/of_device.c
index 0c8ea76..e2c765f 100644
--- a/arch/powerpc/kernel/of_device.c
+++ b/arch/powerpc/kernel/of_device.c
@@ -27,7 +27,7 @@
 			match &= node->type
 				&& !strcmp(matches->type, node->type);
 		if (matches->compatible[0])
-			match &= device_is_compatible(node,
+			match &= of_device_is_compatible(node,
 						      matches->compatible);
 		if (match)
 			return matches;