uboot-imx

board: ge: bx50v3: Support FIT and select configuration based on VPD

Modify configuration to support FIT. Set variable `confidx' from VPD,
in order to load the correct device tree. Modify/simplify U-Boot
environment to support loading FIT image.

Signed-off-by: Ian Ray <ian.ray@ge.com>
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>