board: i.MX6QDL: add Engicam i.CoreM6 1.5 QDL MIPI starter kit

i.CoreM6 1.5 is an another i.CoreM6 QDL cpu modules which can be connected
to EDIMM starter kit design with eMMC and MIPI-CSI interfaces suitable for
Android and video capture application.

notable features:
CPU			NXP i.MX6 S/DL/D/Q, Up to 4 x Cortex-A9@800MHz
Memory  		Up to 2 GB DDR3-1066
Video Interfaces	Up to 1 Parallel Up to 2 LVDS HDMI 1.4
			port 8 bit CSI INPUT MIPI-CSI INPUT
1 x 10/100 Ethernet interface, 2 x USB, 1 x PCIe, 1 x I2S etc

This patch adds support for Quad/Dual and DualLite/Solo SOM's on
MIPI starter kit with boot from SD and eMMC.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>