Without this it won't add core2-64 and similar channels, as the
directory name in deploy_dir/rpm uses _ not - as the package arch.
(From OE-Core rev: 14e3a8f58e309121760fec70619633281dd9d88c)
Signed-off-by: Stefan Stanacar <stefanx.stanacar@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>