block: make Open Firmware device id constant

The match_table field of the struct of_device_id is constant in <linux/of_platform.h>
so it is worth to make ace_of_match also constant.

The semantic match that finds this kind of pattern is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
disable decl_init,const_decl_init;
identifier I1, I2, x;
@@
	struct I1 {
	  ...
	  const struct I2 *x;
	  ...
	};
@s@
identifier r.I1, y;
identifier r.x, E;
@@
	struct I1 y = {
	  .x = E,
	};
@c@
identifier r.I2;
identifier s.E;
@@
	const struct I2 E[] = ... ;
@depends on !c@
identifier r.I2;
identifier s.E;
@@
+	const
	struct I2 E[] = ...;
// </smpl>
Signed-off-by: Márton Németh <nm127@freemail.hu>
Cc: Julia Lawall <julia@diku.dk>
Cc: cocci@diku.dk
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

drivers/block/xsysace.c

@@ -1227,7 +1227,7 @@ static int __devexit ace_of_remove(struct of_device *op)
 }
 
 /* Match table for of_platform binding */
-static struct of_device_id ace_of_match[] __devinitdata = {
+static const struct of_device_id ace_of_match[] __devinitconst = {
 	{ .compatible = "xlnx,opb-sysace-1.00.b", },
 	{ .compatible = "xlnx,opb-sysace-1.00.c", },
 	{ .compatible = "xlnx,xps-sysace-1.00.a", },