Fix multiple container installation issue

Fix multiple container installation issue

When I build lxc-host-image-demo, that out error message;

Nothing RPROVIDES 'lxc-config-cluster-demolxc-config-ivi-demo'
(but ~/meta-agl-devel/meta-agl-lxc/recipes-platform/images/
lxc-host-image-demo.bb RDEPENDS on or otherwise requires it)

The 'lxc-config-cluster-demolxc-config-ivi-demo' is must
describe to 'lxc-config-cluster-demo lxc-config-ivi-demo',
that need space between image name and image name.

This patch fix this issue.

Bug-AGL: SPEC-4109

Signed-off-by: Naoto Yamaguchi <naoto.yamaguchi@aisin.co.jp>
Change-Id: I3e3f057264c0e05872a1f04f9bf5c72af54115e1