[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/drivers/char/hvc_iseries.c b/drivers/char/hvc_iseries.c
index ec420fe..b37f1d5 100644
--- a/drivers/char/hvc_iseries.c
+++ b/drivers/char/hvc_iseries.c
@@ -579,7 +579,7 @@
 		if (!vtermno)
 			continue;
 
-		if (!device_is_compatible(vty, "IBM,iSeries-vty"))
+		if (!of_device_is_compatible(vty, "IBM,iSeries-vty"))
 			continue;
 
 		if (num_found == 0)