ARM: mstar: Add dts for msc313(e) based BreadBee boards

BreadBee is an opensource development board based on the
MStar msc313(e) SoC.

Hardware details, schematics and so on can be found at:
https://github.com/breadbee/breadbee



Signed-off-by: Daniel Palmer <daniel@0x0f.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>