Staging:iio:light:tsl2583: constify attribute_group structures

Check for attribute_group structures that are only stored in the
attrs filed of iio_info structure. As the attrs field of iio_info
structures is constant, so these attribute_group structures can also be
declared constant.
Done using coccinelle

@r1 disable optional_qualifier @
identifier i;
position p;
@@
static struct attribute_group i@p = {...};

@ok1@
identifier r1.i;
position p;
struct iio_info x;
@@
x.attrs=&i@p;

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
static
+const
struct attribute_group i={...};

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct attribute_group i;

File size before: drivers/staging/iio/light/tsl2583.o
   text	   data	    bss	    dec	    hex	filename
   6529	   1052	      0	   7581	   1d9d
drivers/staging/iio/light/tsl2583.o

File size after: drivers/staging/iio/light/tsl2583.o
   text	   data	    bss	    dec	    hex	filename
   6593	    988	      0	   7581	   1d9d
drivers/staging/iio/light/tsl2583.o
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/light/tsl2583.c

@@ -803,7 +803,7 @@ static struct attribute *sysfs_attrs_ctrl[] = {
 	NULL
 };
 
-static struct attribute_group tsl2583_attribute_group = {
+static const struct attribute_group tsl2583_attribute_group = {
 	.attrs = sysfs_attrs_ctrl,
 };