crypto: sahara - make of_device_ids const

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

File size before:
   text	   data	    bss	    dec	    hex	filename
   9759	   2736	      8	  12503	   30d7	drivers/crypto/sahara.o

File size after constify:
   text	   data	    bss	    dec	    hex	filename
  10367	   2128	      8	  12503	   30d7	drivers/crypto/sahara.o
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/sahara.c

@@ -1382,7 +1382,7 @@ static struct platform_device_id sahara_platform_ids[] = {
 };
 MODULE_DEVICE_TABLE(platform, sahara_platform_ids);
 
-static struct of_device_id sahara_dt_ids[] = {
+static const struct of_device_id sahara_dt_ids[] = {
 	{ .compatible = "fsl,imx53-sahara" },
 	{ .compatible = "fsl,imx27-sahara" },
 	{ /* sentinel */ }