arm: at91: Enable watchdog support

This patch enables and starts the watchdog on the AT91 platform if
configured. The WD timeout value is read in the AT91 WD device driver
from the DT, using the "timeout-sec" DT property. If not provided in
the DT, the default value of 2 seconds is used.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Cc: Andreas Bießmann <andreas@biessmann.org>
Cc: Eugen Hristev <eugen.hristev@microchip.com>
diff --git a/arch/arm/mach-at91/include/mach/at91_wdt.h b/arch/arm/mach-at91/include/mach/at91_wdt.h
index cd22723..a8fc73b 100644
--- a/arch/arm/mach-at91/include/mach/at91_wdt.h
+++ b/arch/arm/mach-at91/include/mach/at91_wdt.h
@@ -25,6 +25,12 @@
 	u32	sr;
 } at91_wdt_t;
 
+struct at91_wdt_priv {
+	void __iomem *regs;
+	u32 regval;
+	u32 timeout;
+};
+
 #endif
 
 /* Watchdog Control Register */
@@ -43,4 +49,8 @@
 #define AT91_WDT_MR_WDDBGHLT		0x10000000
 #define AT91_WDT_MR_WDIDLEHLT		0x20000000
 
+/* Hardware timeout in seconds */
+#define WDT_MAX_TIMEOUT		16
+#define WDT_DEFAULT_TIMEOUT	2
+
 #endif