uboot-phytec

arm/km: remove unmaintained board kmsuv31

This target is out of maintenance and can be removed.

Signed-off-by: Holger Brunck <holger.brunck@ch.abb.com>
CC: Valentin Longchamp <valentin.longchamp@ch.abb.com>
CC: Stefan Roese <sr@denx.de>
Reviewed-by: Stefan Roese <sr@denx.de>