Watchdog: introduce ARM SBSA watchdog driver

According to Server Base System Architecture (SBSA) specification,
the SBSA Generic Watchdog has two stage timeouts: the first signal
(WS0) is for alerting the system by interrupt, the second one (WS1) is a
real hardware reset.
More details about the hardware specification of this device:
ARM DEN0029B - Server Base System Architecture (SBSA)

This driver can operate ARM SBSA Generic Watchdog as a single stage
In the single stage mode, when the timeout is reached, your system
will be reset by WS1. The first signal (WS0) is ignored.

Signed-off-by: Zhao Qiang <qiang.zhao@nxp.com>
Signed-off-by: Biwen Li <biwen.li@nxp.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index bf06180..6d5c4fc 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -163,6 +163,15 @@
 	  can be probed and supports all of the methods of WDT, but does not
 	  really do anything.
 
+config WDT_SBSA
+	bool "SBSA watchdog timer support"
+	depends on WDT
+	help
+	   Select this to enable SBSA watchdog timer.
+	   This driver can operate ARM SBSA Generic Watchdog as a single stage.
+	   In the single stage mode, when the timeout is reached, your system
+	   will be reset by WS1. The first signal (WS0) is ignored.
+
 config WDT_SP805
 	bool "SP805 watchdog timer support"
 	depends on WDT