iio: proximity: aw96103: Constify struct iio_info​

'struct iio_info' is not modified in this driver.

Constifying this structure moves some data to a read-only section, so
increase overall security, especially when the structure holds some
function pointers.

On a x86_64, with allmodconfig:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  17366	   1454	     16	  18836	   4994	drivers/iio/proximity/aw96103.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  17526	   1294	     16	  18836	   4994	drivers/iio/proximity/aw96103.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://patch.msgid.link/da4918af46fef03903ab0e9fdcb4f23e014f3821.1733522812.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>