isdn: hisax: hisax_fcpcipnp: 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
   5989	    576	      0	   6565	   19a5 isdn/hisax/hisax_fcpcipnp.o

File size After adding 'const':
   text	   data	    bss	    dec	    hex	filename
   6085	    480	      0	   6565	   19a5 isdn/hisax/hisax_fcpcipnp.o
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/isdn/hisax/hisax_fcpcipnp.c

@@ -52,7 +52,7 @@ module_param(debug, int, 0);
 MODULE_AUTHOR("Kai Germaschewski <kai.germaschewski@gmx.de>/Karsten Keil <kkeil@suse.de>");
 MODULE_DESCRIPTION("AVM Fritz!PCI/PnP ISDN driver");
 
-static struct pci_device_id fcpci_ids[] = {
+static const struct pci_device_id fcpci_ids[] = {
 	{ .vendor      = PCI_VENDOR_ID_AVM,
 	  .device      = PCI_DEVICE_ID_AVM_A1,
 	  .subvendor   = PCI_ANY_ID,