wdt: aspeed: Add AST2600 watchdog support

AST2600 has 8 watchdog timers including 8 sets of
32-bit decrement counters, based on 1MHz clock.

A 64-bit reset mask is also supported to specify
which controllers should be reset by the WDT reset.

Signed-off-by: Chia-Wei, Wang <chiawei_wang@aspeedtech.com>
Reviewed-by: Ryan Chen <ryan_chen@aspeedtech.com>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 4532a40..d5edabf 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -86,6 +86,15 @@
 	  It currently does not support Boot Flash Addressing Mode Detection or
 	  Second Boot.
 
+config WDT_AST2600
+	bool "Aspeed AST2600 watchdog timer support"
+	depends on WDT
+	default y if ASPEED_AST2600
+	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.
+
 config WDT_AT91
 	bool "AT91 watchdog timer support"
 	depends on WDT