Add Armadeus systems APF27 SOM basic support

Buildroot toolchain, UBIFS rootfs, Linux kernel (board is mainlined since 3.8).

Signed-off-by: Julien Boibessot <julien.boibessot@armadeus.com>
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>