mtd: nand: 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 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>
Signed-off-by: Márton Németh <nm127@freemail.hu>
Cc: Julia Lawall <julia@diku.dk>
Cc: cocci@diku.dk
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/nand/fsl_upm.c

@@ -349,7 +349,7 @@ static int __devexit fun_remove(struct of_device *ofdev)
 	return 0;
 }
 
-static struct of_device_id of_fun_match[] = {
+static const struct of_device_id of_fun_match[] = {
 	{ .compatible = "fsl,upm-nand" },
 	{},
 };

drivers/mtd/nand/pasemi_nand.c

@@ -209,7 +209,7 @@ static int __devexit pasemi_nand_remove(struct of_device *ofdev)
 	return 0;
 }
 
-static struct of_device_id pasemi_nand_match[] =
+static const struct of_device_id pasemi_nand_match[] =
 {
 	{
 		.compatible   = "pasemi,localbus-nand",

drivers/mtd/nand/socrates_nand.c

@@ -290,7 +290,7 @@ static int __devexit socrates_nand_remove(struct of_device *ofdev)
 	return 0;
 }
 
-static struct of_device_id socrates_nand_match[] =
+static const struct of_device_id socrates_nand_match[] =
 {
 	{
 		.compatible   = "abb,socrates-nand",