Fix i.MX6

Follwoing targets are broken (cannot be built) since Chinook release since freescale BSP has changed its layer convention since morty (2.2) and also lack of support (as I can see) for AGL build from meta-freescale community.

imx6qsabrelite
wandboard

I managed to build current master (pre-dd) and boot on imx6qsabreauto board, and to do so also in AGL distribution followings are needed.

• Update repo manifest so that it contains the latest freescale layers (meta-freescale, meta-freescale-3rdparty and meta-freescale-distro)
• Fragment files in template/machine/xxxx and aglsetup.sh needs to be update so that it has proper inclusion and settings for bblayers.conf and local.conf
• Kernel recipes needs imx specific bbappends so that we have smack, etc. that are common definitions for AGL builds
• weston-init bbappends also need to take care of freescale device (e.g. /dev/galcore permission)

I hope i.mx boards can be built using AGL distribution so that multiple of i.mx6 boards in my lab do not become trash, and also we will not give developers disappointment when they find they cannot build image for their board.

I have imx6sabreauto and imx6qsabrelite, but mainly doing projects on imx6qsabreauto (sabre platform for automotive infortainment).

At least, I want imx6qsabreauto to be built properly, even though it is classified as one of the community boards.

7/7 status:

With the latest gerrit change 10081, the board boots and looks like OK, also showing USB devices.

imx6qsabreauto is now the only i.MX6 board available in AGL build option (it is good to avoid confusion).