watchdog: zx2967: constify zx2967_wdt_ops.

File size before:
   text	   data	    bss	    dec	    hex	filename
    988	    288	      0	   1276	    4fc	drivers/watchdog/zx2967_wdt.o

File size After adding 'const':
   text	   data	    bss	    dec	    hex	filename
   1084	    192	      0	   1276	    4fc	drivers/watchdog/zx2967_wdt.o
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

drivers/watchdog/zx2967_wdt.c

@@ -154,7 +154,7 @@ static const struct watchdog_info zx2967_wdt_ident = {
 	.identity         =	"zx2967 watchdog",
 };
 
-static struct watchdog_ops zx2967_wdt_ops = {
+static const struct watchdog_ops zx2967_wdt_ops = {
 	.owner = THIS_MODULE,
 	.start = zx2967_wdt_start,
 	.stop = zx2967_wdt_stop,