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

https://inversepath.com/usbarmorySigned-off-by: NAndrej Rosano <andrej@inversepath.com>
Tested-by: NVagrant Cascadian <vagrant@debian.org>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>