tune-ppce500mc.inc: pass -mcpu=e500mc for ppce500mc kernel compile
Currently the -mcpu parameter is not passed to cross gcc when assembling
kernel .S file, the implicit -mcpu option that defaults to the latest
server cpu might casuse incorrect assembling.
A existent case is that wait instruction of ppce500mc is incorrectly assembled
to power9 version with default -mcpu setting, accordingly kernel boot calltrace
happend when wait instruction is executed on ppce500mc targets.
Signed-off-by: Zhenhua Luo <zhenhua.luo@nxp.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
