tty: synclink_gt: 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
  41180	    480	    185	  41845	   a375	drivers/tty/synclink_gt.o

File size After adding 'const':
   text	   data	    bss	    dec	    hex	filename
  41340	    320	    185	  41845	   a375	drivers/tty/synclink_gt.o
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/synclink_gt.c

@@ -95,7 +95,7 @@ MODULE_LICENSE("GPL");
 #define MGSL_MAGIC 0x5401
 #define MAX_DEVICES 32
 
-static struct pci_device_id pci_table[] = {
+static const struct pci_device_id pci_table[] = {
 	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_GT_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
 	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_GT2_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
 	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_GT4_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},