aspeed: Watchdog Timer Driver

This driver supports ast2500 and ast2400 SoCs.
Only ast2500 supports reset_mask and thus the option of resettting
individual peripherals using WDT.

Signed-off-by: Maxim Sloyko <maxims@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index e8d2dba..2034e3c 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -23,4 +23,15 @@
 		can be probed and supports all of the methods of WDT, but does not
 		really do anything.
 
+config WDT_ASPEED
+	bool "Aspeed ast2400/ast2500 watchdog timer support"
+	depends on WDT
+	default y if ARCH_ASPEED
+	help
+	  Select this to enable watchdog timer for Aspeed ast2500/ast2400 devices.
+	  The watchdog timer is stopped when initialized. It performs reset, either
+	  full SoC reset or CPU or just some peripherals, based on the flags.
+	  It currently does not support Boot Flash Addressing Mode Detection or
+	  Second Boot.
+
 endmenu