ieee802154: Add NXP MCR20A IEEE 802.15.4 transceiver driver

The MCR20AVHM transceiver (or MCR20A) is a low power,
high-performance 2.4 GHz, IEEE 802.15.4 compliant transceiver.

This driver implements a subset of ieee802154_ops.
It has no support for CSMA due to lack of hardware support.
It has currently no support for its proprietary Dual-PAN feature.

https://www.nxp.com/docs/en/reference-manual/MCR20RM.pdf

Signed-off-by: Xue Liu <liuxuenetmail@gmail.com>
Signed-off-by: Stefan Schmidt <stefan@osg.samsung.com>

drivers/net/ieee802154/Kconfig

@@ -104,3 +104,14 @@ config IEEE802154_CA8210_DEBUGFS
 	  exposes a debugfs node for each CA8210 instance which allows
 	  direct use of the Cascoda API, exposing the 802.15.4 MAC
 	  management entities.
+
+config IEEE802154_MCR20A
+       tristate "MCR20A transceiver driver"
+       depends on IEEE802154_DRIVERS && MAC802154
+       depends on SPI
+	---help---
+	  Say Y here to enable the MCR20A SPI 802.15.4 wireless
+	  controller.
+
+	  This driver can also be built as a module. To do so, say M here.
+	  the module will be called 'mcr20a'.

drivers/net/ieee802154/Makefile

@@ -6,3 +6,4 @@ obj-$(CONFIG_IEEE802154_CC2520) += cc2520.o
 obj-$(CONFIG_IEEE802154_ATUSB) += atusb.o
 obj-$(CONFIG_IEEE802154_ADF7242) += adf7242.o
 obj-$(CONFIG_IEEE802154_CA8210) += ca8210.o
+obj-$(CONFIG_IEEE802154_MCR20A) += mcr20a.o