video: fbdev: pm3fb: constify pci_device_id.

pci_device_id are not supposed to change at runtime. All functions
working with pci_device_id provided by <linux/pci.h> work with
const pci_device_id. So mark the non-const structs as const.

File size before:
   text	   data	    bss	    dec	    hex	filename
  10332	    596	     16	  10944	   2ac0	drivers/video/fbdev/pm3fb.o

File size after adding 'const':
   text	   data	    bss	    dec	    hex	filename
  10396	    532	     16	  10944	   2ac0	drivers/video/fbdev/pm3fb.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Maik Broemme <mbroemme@libmpq.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

drivers/video/fbdev/pm3fb.c

@@ -1479,7 +1479,7 @@ static void pm3fb_remove(struct pci_dev *dev)
 	}
 }
 
-static struct pci_device_id pm3fb_id_table[] = {
+static const struct pci_device_id pm3fb_id_table[] = {
 	{ PCI_VENDOR_ID_3DLABS, 0x0a,
 	  PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
 	{ 0, }