EDAC: Constify of_device_id array

of_device_id is always used as const. See driver.of_match_table and open
firmware functions.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: Robert Richter <rric@kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Johannes Thumshirn <johannes.thumshirn@men.de>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Sören Brinkmann <soren.brinkmann@xilinx.com>
Cc: linux-edac@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1426535685-25996-10-git-send-email-fabf@skynet.be
Signed-off-by: Borislav Petkov <bp@suse.de>

drivers/edac/ppc4xx_edac.c

@@ -193,7 +193,7 @@ static int ppc4xx_edac_remove(struct platform_device *device);
  * Device tree node type and compatible tuples this driver can match
  * on.
  */
-static struct of_device_id ppc4xx_edac_match[] = {
+static const struct of_device_id ppc4xx_edac_match[] = {
 	{
 		.compatible	= "ibm,sdram-4xx-ddr2"
 	},