pcmcia: Convert pcmcia_device_id declarations to const

Saves about 50KB of data.

Old/new size of all objects:
   text	   data	    bss	    dec	    hex	filename
 563015	  80096	 130684	 773795	  bcea3	(TOTALS)
 610916	  32256	 130632	 773804	  bceac	(TOTALS)

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Kurt Van Dijck <kurt.van.dijck@eia.be> (for drivers/net/can/softing/softing_cs.c)
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
diff --git a/drivers/bluetooth/btuart_cs.c b/drivers/bluetooth/btuart_cs.c
index f8a0708..526b618 100644
--- a/drivers/bluetooth/btuart_cs.c
+++ b/drivers/bluetooth/btuart_cs.c
@@ -689,7 +689,7 @@
 	pcmcia_disable_device(link);
 }
 
-static struct pcmcia_device_id btuart_ids[] = {
+static const struct pcmcia_device_id btuart_ids[] = {
 	/* don't use this driver. Use serial_cs + hci_uart instead */
 	PCMCIA_DEVICE_NULL
 };