staging:iio:tsl2563 drop pointless forward declaration

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Peter Meerwald <pmeerw@pmeerw.net>
diff --git a/drivers/staging/iio/light/tsl2563.c b/drivers/staging/iio/light/tsl2563.c
index 1a3092a..b91d9bb 100644
--- a/drivers/staging/iio/light/tsl2563.c
+++ b/drivers/staging/iio/light/tsl2563.c
@@ -677,8 +677,6 @@
 	return !!(ret & 0x30);
 }
 
-static struct i2c_driver tsl2563_i2c_driver;
-
 static const struct iio_info tsl2563_info_no_irq = {
 	.driver_module = THIS_MODULE,
 	.read_raw = &tsl2563_read_raw,