ARM: imx_v6_v7_defconfig: enable parallel display

Enable paralell display by default

Signed-off-by: Rogerio Pimentel <rogerio.pimentel@freescale.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>