tty: synclink: 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
  51755	    400	    513	  52668	   cdbc	drivers/tty/synclink.o

File size After adding 'const':
   text	   data	    bss	    dec	    hex	filename
  51883	    304	    513	  52700	   cddc	drivers/tty/synclink.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/synclink.c

@@ -884,7 +884,7 @@ static int synclink_init_one (struct pci_dev *dev,
 				     const struct pci_device_id *ent);
 static void synclink_remove_one (struct pci_dev *dev);
 
-static struct pci_device_id synclink_pci_tbl[] = {
+static const struct pci_device_id synclink_pci_tbl[] = {
 	{ PCI_VENDOR_ID_MICROGATE, PCI_DEVICE_ID_MICROGATE_USC, PCI_ANY_ID, PCI_ANY_ID, },
 	{ PCI_VENDOR_ID_MICROGATE, 0x0210, PCI_ANY_ID, PCI_ANY_ID, },
 	{ 0, }, /* terminate list */