watchdog: add watchdog driver for MediaTek MT7620 SoC

This patch adds watchdog support for the Mediatek MT7620 SoC

Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index d5edabf..602ccbe 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -134,6 +134,13 @@
 	help
 	  Select this to enable mpc8xx watchdog timer
 
+config WDT_MT7620
+	bool "MediaTek MT7620 watchdog timer support"
+	depends on WDT && SOC_MT7620
+	help
+	  Select this to enable watchdog timer on MediaTek MT7620 and earlier
+	  SoC chips.
+
 config WDT_MT7621
 	bool "MediaTek MT7621 watchdog timer support"
 	depends on WDT && SOC_MT7628