isdn: hisax: hfc4s8s_l1: 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
  10512	    536	      4	  11052	   2b2c	drivers/isdn/hisax/hfc4s8s_l1.o

File size After adding 'const':
   text	   data	    bss	    dec	    hex	filename
  10672	    376	      4	  11052	   2b2c	drivers/isdn/hisax/hfc4s8s_l1.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/hisax/hfc4s8s_l1.c

@@ -86,7 +86,7 @@ typedef struct {
 	char *device_name;
 } hfc4s8s_param;
 
-static struct pci_device_id hfc4s8s_ids[] = {
+static const struct pci_device_id hfc4s8s_ids[] = {
 	{.vendor = PCI_VENDOR_ID_CCD,
 	 .device = PCI_DEVICE_ID_4S,
 	 .subvendor = 0x1397,