[media] rc-core: ir_core_dev_number can be static

Fix sparse warning:
	drivers/media/rc/rc-main.c:27:1: sparse: symbol 'ir_core_dev_number' was not declared. Should it be static?
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/rc/rc-main.c

@@ -24,7 +24,7 @@
 
 /* Bitmap to store allocated device numbers from 0 to IRRCV_NUM_DEVICES - 1 */
 #define IRRCV_NUM_DEVICES      256
-DECLARE_BITMAP(ir_core_dev_number, IRRCV_NUM_DEVICES);
+static DECLARE_BITMAP(ir_core_dev_number, IRRCV_NUM_DEVICES);
 
 /* Sizes are in bytes, 256 bytes allows for 32 entries on x64 */
 #define IR_TAB_MIN_SIZE	256