media: rc-core: rename input_name to device_name

When an ir-spi is registered, you get this message.

rc rc0: Unspecified device as /devices/platform/soc/3f215080.spi/spi_master/spi32766/spi32766.128/rc/rc0

"Unspecified device" refers to input_name, which makes no sense for IR
TX only devices. So, rename to device_name.

Also make driver_name const char* so that no casts are needed anywhere.

Now ir-spi reports:

rc rc0: IR SPI as /devices/platform/soc/3f215080.spi/spi_master/spi32766/spi32766.128/rc/rc0

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/drivers/media/rc/sunxi-cir.c b/drivers/media/rc/sunxi-cir.c
index 4b785dd..87933eb 100644
--- a/drivers/media/rc/sunxi-cir.c
+++ b/drivers/media/rc/sunxi-cir.c
@@ -215,7 +215,7 @@
 	}
 
 	ir->rc->priv = ir;
-	ir->rc->input_name = SUNXI_IR_DEV;
+	ir->rc->device_name = SUNXI_IR_DEV;
 	ir->rc->input_phys = "sunxi-ir/input0";
 	ir->rc->input_id.bustype = BUS_HOST;
 	ir->rc->input_id.vendor = 0x0001;