arch/arm/dts: add dts support for wandboard quad

Adds device tree support for Wandboard Quad, and early support for more
extensive device tree support on Wandboard in general.
wandboard_defconfig: add file
imx6qdl-wandboard.dtsi: Fix for MIPI-CSI camera

Modified clock number for the ov5640_mipi interface.  Other edits include
some work on the wifi/bt tree that are in-development.
wandboard_defconfig: add CONFIG_FHANDLE

CONFIG_FHANDLE is needed to use systemd
wandboard_defconfig: add CONFIG_SLUB_DEBUG
ARM i.MX6 Wandboard add wifi+bt rfkill driver

BRCM WiFi module requires initialization for control gpio;
Additional provides rfkill funcs.

v2: fix wrong probe func in driver struct
v3: add imx6qdl compatible

Signed-off-by: Vladimir Ermakov <vooon341@gmail.com>
Signed-off-by: John Weber <rjohnweber@gmail.com>
wandboard: dts fixes
wandboard_defconfig:  Enable RFKILL
wandboard: Cleanup dts

Remove unnecessary comments, experimental functions, and unsupported
functions such as CEC.