ARM: rmobile: Add Beacon EmbeddedWorks RZG2N Dev Kit

The Beacon EmbeddedWorks kit is based on the R8A774B1 SoC also
known as the RZ/G2N.

The kit consists of a SOM + Baseboard and supports microSD,
eMMC, Ethernet, a couple celular radios, two CAN interfaces,
Bluetooth and WiFi.  It shares much of the same design as
the RZ/G2M dev kit.

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/board/beacon/beacon-rzg2m/MAINTAINERS b/board/beacon/beacon-rzg2m/MAINTAINERS
index 3383a68..f50df3b 100644
--- a/board/beacon/beacon-rzg2m/MAINTAINERS
+++ b/board/beacon/beacon-rzg2m/MAINTAINERS
@@ -4,3 +4,4 @@
 F:	board/beacon/beacon-rzg2m/
 F:	include/configs/beacon-rzg2m.h
 F:	configs/r8a774a1_beacon_defconfig
+F:	configs/r8a774b1_beacon_defconfig