ARM: mx5: add support for USB armory board

Add support for Inverse Path USB armory board, an open source
flash-drive sized computer based on Freescale i.MX53 SoC.

http://inversepath.com/usbarmory



Signed-off-by: Andrej Rosano <andrej@inversepath.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Chris Kuethe <chris.kuethe@gmail.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Vagrant Cascadian <vagrant@debian.org>
Tested-By: Vagrant Cascadian <vagrant@debian.org>
Tested-by: Chris Kuethe <chris.kuethe@gmail.com>