With newer ARC toolchain obsolete -marcXXX were finally deperecated
and so compiler throws errors now about unknown option.
Solution is as simple as switching to more generic -mcu-XXX
options. Which we do. Unfortunately that change in upstream U-Boot 
happened right after v2016.09 was released an so we need to have that fix
for v2016.07 which is mentioned in axs10x defconfigs and for the latest
U-Boot release v2016.09 (which is selected by default if no defconfig is
Once we deprecate either U-Boot version in U-Boot corresponding patch
should be removed essentially.
Signed-off-by: Alexey Brodkin <firstname.lastname@example.org>
Cc: Thomas Petazzoni <email@example.com>
Cc: Peter Korsgaard <firstname.lastname@example.org>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <email@example.com>
[Thomas: handle the U-Boot bump to 2016.09.01.]
Signed-off-by: Thomas Petazzoni <firstname.lastname@example.org>