drivers/ieee802154: add support for the at86rf230/231 transceivers

The AT86RF231 is a feature rich, low-power 2.4 GHz radio transceiver
designed for industrial and consumer ZigBee/IEEE 802.15.4, 6LoWPAN,
RF4CE and high data rate 2.4 GHz ISM band applications.

This patch adds support for the Atmel RF230/231 radio transceivers.

Signed-off-by: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/ieee802154/Kconfig

@@ -19,6 +19,7 @@ config IEEE802154_FAKEHARD
 
           This driver can also be built as a module. To do so say M here.
 	  The module will be called 'fakehard'.
+
 config IEEE802154_FAKELB
 	depends on IEEE802154_DRIVERS && MAC802154
 	tristate "IEEE 802.15.4 loopback driver"
@@ -28,3 +29,8 @@ config IEEE802154_FAKELB
 
 	  This driver can also be built as a module. To do so say M here.
 	  The module will be called 'fakelb'.
+
+config IEEE802154_AT86RF230
+        depends on IEEE802154_DRIVERS && MAC802154
+        tristate "AT86RF230/231 transceiver driver"
+        depends on SPI

drivers/ieee802154/Makefile

@@ -1,2 +1,3 @@
 obj-$(CONFIG_IEEE802154_FAKEHARD) += fakehard.o
 obj-$(CONFIG_IEEE802154_FAKELB) += fakelb.o
+obj-$(CONFIG_IEEE802154_AT86RF230) += at86rf230.o