watchdog: tegra: constify watchdog_ops structures

Check for watchdog_ops structures that are only stored in the ops field of
a watchdog_device structure.  This field is declared const, so watchdog_ops
structures that have this property can be declared as const also.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r disable optional_qualifier@
identifier i;
position p;
@@
static struct watchdog_ops i@p = { ... };

@ok@
identifier r.i;
struct watchdog_device e;
position p;
@@
e.ops = &i@p;

@bad@
position p != {r.p,ok.p};
identifier r.i;
struct watchdog_ops e;
@@
e@i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
 struct watchdog_ops i = { ... };
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/tegra_wdt.c

@@ -178,7 +178,7 @@ static const struct watchdog_info tegra_wdt_info = {
 	.identity	= "Tegra Watchdog",
 };
 
-static struct watchdog_ops tegra_wdt_ops = {
+static const struct watchdog_ops tegra_wdt_ops = {
 	.owner = THIS_MODULE,
 	.start = tegra_wdt_start,
 	.stop = tegra_wdt_stop,