media: rc: constify attribute_group structures

attribute_groups are not supposed to change at runtime. All functions
working with attribute_groups provided by <linux/sysfs.h> work with const
attribute_group. So mark the non-const structs as const.

File size before:
   text	   data	    bss	    dec	    hex	filename
  11605	    880	     20	  12505	   30d9	drivers/media/rc/rc-main.o

File size After adding 'const':
   text	   data	    bss	    dec	    hex	filename
  11797	    720	     20	  12537	   30f9	drivers/media/rc/rc-main.o
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NSean Young <sean@mess.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/rc/rc-main.c

@@ -1507,7 +1507,7 @@ static struct attribute *rc_dev_protocol_attrs[] = {
 	NULL,
 };
 
-static struct attribute_group rc_dev_protocol_attr_grp = {
+static const struct attribute_group rc_dev_protocol_attr_grp = {
 	.attrs	= rc_dev_protocol_attrs,
 };
 
@@ -1517,7 +1517,7 @@ static struct attribute *rc_dev_filter_attrs[] = {
 	NULL,
 };
 
-static struct attribute_group rc_dev_filter_attr_grp = {
+static const struct attribute_group rc_dev_filter_attr_grp = {
 	.attrs	= rc_dev_filter_attrs,
 };
 
@@ -1528,7 +1528,7 @@ static struct attribute *rc_dev_wakeup_filter_attrs[] = {
 	NULL,
 };
 
-static struct attribute_group rc_dev_wakeup_filter_attr_grp = {
+static const struct attribute_group rc_dev_wakeup_filter_attr_grp = {
 	.attrs	= rc_dev_wakeup_filter_attrs,
 };