[ARM] sa1100_wdt: don't assume CLOCK_TICK_RATE to be a constant

See description of commit:

   [ARM] rtc-sa1100: don't assume CLOCK_TICK_RATE to be a constant

for additional information.
Signed-off-by: Eric Miao <eric.miao@marvell.com>

drivers/watchdog/sa1100_wdt.c

@@ -35,8 +35,7 @@
 #include <mach/reset.h>
 #include <mach/hardware.h>
 
-#define OSCR_FREQ		CLOCK_TICK_RATE
-
+static unsigned long oscr_freq;
 static unsigned long sa1100wdt_users;
 static int pre_margin;
 static int boot_status;
@@ -123,12 +122,12 @@ static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
 			break;
 		}
 
-		pre_margin = OSCR_FREQ * time;
+		pre_margin = oscr_freq * time;
 		OSMR3 = OSCR + pre_margin;
 		/*fall through*/
 
 	case WDIOC_GETTIMEOUT:
-		ret = put_user(pre_margin / OSCR_FREQ, p);
+		ret = put_user(pre_margin / oscr_freq, p);
 		break;
 	}
 	return ret;
@@ -155,6 +154,8 @@ static int __init sa1100dog_init(void)
 {
 	int ret;
 
+	oscr_freq = get_clock_tick_rate();
+
 	/*
 	 * Read the reset status, and save it for later.  If
 	 * we suspend, RCSR will be cleared, and the watchdog
@@ -162,7 +163,7 @@ static int __init sa1100dog_init(void)
 	 */
 	boot_status = (reset_status & RESET_STATUS_WATCHDOG) ?
 				WDIOF_CARDRESET : 0;
-	pre_margin = OSCR_FREQ * margin;
+	pre_margin = oscr_freq * margin;
 
 	ret = misc_register(&sa1100dog_miscdev);
 	if (ret == 0)