at86rf230: increase sleep to off timings

I expierenced when setting channel while sleep mode it didn't changed
the channel inside the hardware registers. Then I got another report of
an user which has similar issues.

I increased the sleep to off state change timing, which is according
at86rf233 at maximum 1000 us. After this change I got no similar effects
again.

I tried another option to wait on AWAKE_END irq, which can be used to
wait until the transceiver is awaked. I tested it and the IRQ took 4
seconds after starting state change. I don't believe it takes 4 seconds
to go into the TRX_OFF state from SLEEP state. The alternative is to
increase the timings which seems to work.

Cc: Oleg Hahm <oliver.hahm@inria.fr>
Signed-off-by: Alexander Aring <aar@pengutronix.de>
Reviewed-by: Stefan Schmidt<stefan@osg.samsung.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/net/ieee802154/at86rf230.c

@@ -1340,7 +1340,7 @@ static struct at86rf2xx_chip_data at86rf233_data = {
 	.t_off_to_aack = 80,
 	.t_off_to_tx_on = 80,
 	.t_off_to_sleep = 35,
-	.t_sleep_to_off = 210,
+	.t_sleep_to_off = 1000,
 	.t_frame = 4096,
 	.t_p_ack = 545,
 	.rssi_base_val = -91,
@@ -1355,7 +1355,7 @@ static struct at86rf2xx_chip_data at86rf231_data = {
 	.t_off_to_aack = 110,
 	.t_off_to_tx_on = 110,
 	.t_off_to_sleep = 35,
-	.t_sleep_to_off = 380,
+	.t_sleep_to_off = 1000,
 	.t_frame = 4096,
 	.t_p_ack = 545,
 	.rssi_base_val = -91,
@@ -1370,7 +1370,7 @@ static struct at86rf2xx_chip_data at86rf212_data = {
 	.t_off_to_aack = 200,
 	.t_off_to_tx_on = 200,
 	.t_off_to_sleep = 35,
-	.t_sleep_to_off = 380,
+	.t_sleep_to_off = 1000,
 	.t_frame = 4096,
 	.t_p_ack = 545,
 	.rssi_base_val = -100,