Convert at91 watchdog driver to new SoC access

This converts the at91 watchdog driver to new c structure
type to access registers of the SoC

Signed-off-by: Achim Ehrlich <aehrlich@taskit.de>
diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
index 5bb8b77..25afae7 100644
--- a/drivers/watchdog/at91sam9_wdt.c
+++ b/drivers/watchdog/at91sam9_wdt.c
@@ -42,11 +42,10 @@
 static int at91_wdt_settimeout(unsigned int timeout)
 {
 	unsigned int reg;
-	unsigned int mr;
+	at91_wdt_t *wd 	= (at91_wdt_t *) AT91_WDT_BASE;
 
 	/* Check if disabled */
-	mr = at91_sys_read(AT91_WDT_MR);
-	if (mr & AT91_WDT_WDDIS) {
+	if (readl(&wd->mr) & AT91_WDT_MR_WDDIS) {
 		printf("sorry, watchdog is disabled\n");
 		return -1;
 	}
@@ -57,19 +56,21 @@
 	 * Since WDV is a 12-bit counter, the maximum period is
 	 * 4096 / 256 = 16 seconds.
 	 */
-	reg = AT91_WDT_WDRSTEN	/* causes watchdog reset */
-		/* | AT91_WDT_WDRPROC	causes processor reset only */
-		| AT91_WDT_WDDBGHLT		/* disabled in debug mode */
-		| AT91_WDT_WDD			/* restart at any time */
-		| (timeout & AT91_WDT_WDV);	/* timer value */
-	at91_sys_write(AT91_WDT_MR, reg);
+
+	reg = AT91_WDT_MR_WDRSTEN		/* causes watchdog reset */
+		| AT91_WDT_MR_WDDBGHLT		/* disabled in debug mode */
+		| AT91_WDT_MR_WDD(0xfff)	/* restart at any time */
+		| AT91_WDT_MR_WDV(timeout);	/* timer value */
+
+	writel(reg, &wd->mr);
 
 	return 0;
 }
 
 void hw_watchdog_reset(void)
 {
-	at91_sys_write(AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
+	at91_wdt_t *wd 	= (at91_wdt_t *) AT91_WDT_BASE;
+	writel(AT91_WDT_CR_WDRSTT | AT91_WDT_CR_KEY, &wd->cr);
 }
 
 void hw_watchdog_init(void)