USB gadget: 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 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>

---

diff -u -p a/drivers/usb/gadget/fsl_qe_udc.c b/drivers/usb/gadget/fsl_qe_udc.c
@@ -2749,7 +2749,7 @@ static int __devexit qe_udc_remove(struc
 }
 
 /*-------------------------------------------------------------------------*/
-static struct of_device_id __devinitdata qe_udc_match[] = {
+static const struct of_device_id qe_udc_match[] __devinitconst = {
 	{
 		.compatible = "fsl,mpc8323-qe-usb",
 		.data = (void *)PORT_QE,