Add support for Eukrea's MBIMX27

MBIMX27 is the evaluation board for CPUIMX27 and integrates : a
QVGA TFT, a SPI touchscreen controler, a SDCard connector wired to
SDHC1.

Signed-off-by: Eric Benard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>