at86rf230: add warning if edge-triggered irq

While testing I experience a deadlock while using the at86rf233 on a
raspberry pi. The reason was an edge triggered gpio irq because the irq
triggered while irq was disabled. This issue doesn't happend on a level
triggered irq because the irq will hit after calling enable_irq.

This patch adds a warning that it's not recommended to use a edge-triggered
irq type. Also change the examples to high-level irqtype.

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 c7a30ce..1d438bc 100644
--- a/drivers/net/ieee802154/at86rf230.c
+++ b/drivers/net/ieee802154/at86rf230.c
@@ -1321,6 +1321,10 @@
 		return rc;
 
 	irq_type = irq_get_trigger_type(lp->spi->irq);
+	if (irq_type == IRQ_TYPE_EDGE_RISING ||
+	    irq_type == IRQ_TYPE_EDGE_FALLING)
+		dev_warn(&lp->spi->dev,
+			 "Using edge triggered irq's are not recommended!\n");
 	if (irq_type == IRQ_TYPE_EDGE_FALLING ||
 	    irq_type == IRQ_TYPE_LEVEL_LOW)
 		irq_pol = IRQ_ACTIVE_LOW;