rtc: constify rtc_class_ops structures

Check for rtc_class_ops structures that are only passed to
devm_rtc_device_register, rtc_device_register,
platform_device_register_data, all of which declare the corresponding
parameter as const.  Declare rtc_class_ops structures that have these
properties as const.

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 rtc_class_ops i@p = { ... };

@ok@
identifier r.i;
expression e1,e2,e3,e4;
position p;
@@
(
devm_rtc_device_register(e1,e2,&i@p,e3)
|
rtc_device_register(e1,e2,&i@p,e3)
|
platform_device_register_data(e1,e2,e3,&i@p,e4)
)

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

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
 struct rtc_class_ops i = { ... };
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Hans Ulli Kroll <ulli.kroll@googlemail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

drivers/rtc/rtc-twl.c

@@ -462,7 +462,7 @@ out:
 	return ret;
 }
 
-static struct rtc_class_ops twl_rtc_ops = {
+static const struct rtc_class_ops twl_rtc_ops = {
 	.read_time	= twl_rtc_read_time,
 	.set_time	= twl_rtc_set_time,
 	.read_alarm	= twl_rtc_read_alarm,