atm: idt77252: 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
  27702	    468	     16	  28186	   6e1a	drivers/atm/idt77252.o

File size After adding 'const':
   text	   data	    bss	    dec	    hex	filename
  27766	    404	     16	  28186	   6e1a	drivers/atm/idt77252.o
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/atm/idt77252.c

@@ -3725,7 +3725,7 @@ static int idt77252_init_one(struct pci_dev *pcidev,
 	return err;
 }
 
-static struct pci_device_id idt77252_pci_tbl[] =
+static const struct pci_device_id idt77252_pci_tbl[] =
 {
 	{ PCI_VDEVICE(IDT, PCI_DEVICE_ID_IDT_IDT77252), 0 },
 	{ 0, }