input: make Open Firmware device id constant

From: Márton Németh <[email protected]>

The match_table field of the struct of_device_id is constant in <linux/of_platform.h> so it is worth to make xps2_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>

---

diff -u -p a/drivers/input/serio/xilinx_ps2.c b/drivers/input/serio/xilinx_ps2.c
@@ -354,7 +354,7 @@ static int __devexit xps2_of_remove(stru
 }
 
 /* Match table for of_platform binding */
-static struct of_device_id xps2_of_match[] __devinitdata = {
+static const struct of_device_id xps2_of_match[] __devinitconst = {
 	{ .compatible = "xlnx,xps-ps2-1.00.a", },
 	{ /* end of list */ },
 };