Correct PM828_PCI_config Makefile target.

Makefile

@@ -1187,7 +1187,7 @@ PM828_config	\
 PM828_PCI_config	\
 PM828_ROMBOOT_config	\
 PM828_ROMBOOT_PCI_config:	unconfig
-	@if [ -z "$(findstring _PCI_,$@)" ] ; then \
+	@if [ "$(findstring _PCI_,$@)" ] ; then \
 		echo "#define CONFIG_PCI"  >>include/config.h ; \
 		echo "... with PCI enabled" ; \
 	else \