at91sam9: add watchdog support

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/Makefile b/Makefile
index f9edd9d..9f4e431 100644
--- a/Makefile
+++ b/Makefile
@@ -265,6 +265,7 @@
 LIBS += drivers/twserial/libtws.a
 LIBS += drivers/usb/libusb.a
 LIBS += drivers/video/libvideo.a
+LIBS += drivers/watchdog/libwatchdog.a
 LIBS += common/libcommon.a
 LIBS += libfdt/libfdt.a
 LIBS += api/libapi.a