mips: mt76xx: Enable watchdog support

This patch enables and starts the watchdog on the MT7620 platform.
Currently the WD timeout is configured to 60 seconds.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
[fixed build error due to missing function prototype arch_misc_init]
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 8278c68..1b1b1d7 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -79,6 +79,7 @@
 	select DM_SERIAL
 	imply DM_SPI
 	imply DM_SPI_FLASH
+	select ARCH_MISC_INIT if WATCHDOG
 	select MIPS_TUNE_24KC
 	select OF_CONTROL
 	select ROM_EXCEPTION_VECTORS