wireless: ipw2100: constify attribute_group structures.

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

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/wireless/intel/ipw2x00/ipw2100.c

@@ -4324,7 +4324,7 @@ static struct attribute *ipw2100_sysfs_entries[] = {
 	NULL,
 };
 
-static struct attribute_group ipw2100_attribute_group = {
+static const struct attribute_group ipw2100_attribute_group = {
 	.attrs = ipw2100_sysfs_entries,
 };