video: fbdev: tridentfb: 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
  13206	   1232	     40	  14478	   388e	video/fbdev/tridentfb.o

File size after adding 'const':
   text	   data	    bss	    dec	    hex	filename
  13910	    528	     40	  14478	   388e	video/fbdev/tridentfb.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/tridentfb.c

@@ -1737,7 +1737,7 @@ static void trident_pci_remove(struct pci_dev *dev)
 }
 
 /* List of boards that we are trying to support */
-static struct pci_device_id trident_devices[] = {
+static const struct pci_device_id trident_devices[] = {
 	{PCI_VENDOR_ID_TRIDENT,	BLADE3D, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
 	{PCI_VENDOR_ID_TRIDENT,	CYBERBLADEi7, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
 	{PCI_VENDOR_ID_TRIDENT,	CYBERBLADEi7D, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},