PowerPC: keymile: Add support for kmcent2 board

Add basic support for the Hitachi Power Grids kmcent2 board, based
on the NXP QorIQ T1040 SoC.

Signed-off-by: Valentin Longchamp <valentin.longchamp@hitachi-powergrids.com>
Signed-off-by: Rainer Boschung <rainer.boschung@hitachi-powergrids.com>
Signed-off-by: Niel Fourie <lusus@denx.de>
Cc: Holger Brunck <holger.brunck@hitachi-powergrids.com>
Cc: Heiko Schocher <hs@denx.de>
Reviewed-by: Stefan Roese <sr@denx.de>
[Fixed blank line at EOF errors]
Signed-off-by: Priyanka Jain <priyanka.jain@nxp.com>