[POWERPC] iSeries: fix CONFIG_VIOPATH dependency

This is a long standing typo.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/iseries/Kconfig

@@ -31,5 +31,5 @@ endmenu
 
 config VIOPATH
 	bool
-	depends on VIOCONS || VIODASD || VIOCD || VIOTAPE || VETH
+	depends on VIOCONS || VIODASD || VIOCD || VIOTAPE || ISERIES_VETH
 	default y