[media] ene_cir: get rid of warning: no previous prototype

drivers/media/rc/ene_ir.c:332:6: warning: no previous prototype for 'ene_rx_sense_carrier' [-Wmissing-prototypes]

Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/rc/ene_ir.c

@@ -329,7 +329,7 @@ static int ene_rx_get_sample_reg(struct ene_device *dev)
 }
 
 /* Sense current received carrier */
-void ene_rx_sense_carrier(struct ene_device *dev)
+static void ene_rx_sense_carrier(struct ene_device *dev)
 {
 	DEFINE_IR_RAW_EVENT(ev);