configs: add Freescale SABRE Auto board support

SABRE Board for Automotive Infotainment (SABRE Auto, a.k.a. SABRE-AI) is
Freescale's evaluation board based on the i.MX 6 ARM Cortex-A9 applications
processor.

Those defconfigs are an adaptation of freescale_imx6{q,dl}sabresd_defconfig for
SABRE Auto, and are thus based on Freescale "official" git repo on
git.freescale.com and SW release 3.10.17_1.0.0_ga.

Signed-off-by: Vincent Stehlé <vincent.stehle@freescale.com>
Cc: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Cc: Gilles Talis <gilles.talis@gmail.com>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Luca Ceresoli <luca@lucaceresoli.net>
Cc: Gary Bisson <bisson.gary@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>