watchdog: add MT7621 watchdog support

This patch adds support for the watchdog core found on newer MediaTek Wifi
SoCs MT7621 and MT7628. There is no symbol for MT7628 as it is a subtype of
MT7620 so we depend on that instead.

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 2d203fc..f566753 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -152,6 +152,7 @@
 obj-$(CONFIG_LANTIQ_WDT) += lantiq_wdt.o
 obj-$(CONFIG_RALINK_WDT) += rt2880_wdt.o
 obj-$(CONFIG_IMGPDC_WDT) += imgpdc_wdt.o
+obj-$(CONFIG_MT7621_WDT) += mt7621_wdt.o
 
 # PARISC Architecture