at86rf230: add regmap support

This patch adds regmap support for the at86rf230 driver and drop the
lowlevel spi access functions and use the regmap access functions.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ieee802154/Kconfig b/drivers/net/ieee802154/Kconfig
index 8b7ae51..391a916 100644
--- a/drivers/net/ieee802154/Kconfig
+++ b/drivers/net/ieee802154/Kconfig
@@ -34,6 +34,7 @@
 	depends on IEEE802154_DRIVERS && MAC802154
 	tristate "AT86RF230/231/233/212 transceiver driver"
 	depends on SPI
+	select REGMAP_SPI
 	---help---
 	  Say Y here to enable the at86rf230/231/233/212 SPI 802.15.4 wireless
 	  controller.