at86rf230: correct at86rf2xx lifs timings

Symbol rate is 16 us. Lifs is 40 symbols. 16 * 40 = 640 us.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/drivers/net/ieee802154/at86rf230.c b/drivers/net/ieee802154/at86rf230.c
index 2a25324..b26135f 100644
--- a/drivers/net/ieee802154/at86rf230.c
+++ b/drivers/net/ieee802154/at86rf230.c
@@ -1267,7 +1267,7 @@
 	.t_frame = 4096,
 	.t_p_ack = 545,
 	.t_sifs = 192,
-	.t_lifs = 480,
+	.t_lifs = 640,
 	.t_tx_timeout = 2000,
 	.rssi_base_val = -91,
 	.set_channel = at86rf23x_set_channel,
@@ -1283,7 +1283,7 @@
 	.t_frame = 4096,
 	.t_p_ack = 545,
 	.t_sifs = 192,
-	.t_lifs = 480,
+	.t_lifs = 640,
 	.t_tx_timeout = 2000,
 	.rssi_base_val = -91,
 	.set_channel = at86rf23x_set_channel,
@@ -1299,7 +1299,7 @@
 	.t_frame = 4096,
 	.t_p_ack = 545,
 	.t_sifs = 192,
-	.t_lifs = 480,
+	.t_lifs = 640,
 	.t_tx_timeout = 2000,
 	.rssi_base_val = -100,
 	.set_channel = at86rf212_set_channel,