build/repositories: add attach_pool_rh_cdn function
build/repositories: add attach_pool_rh_cdn function

Add attach_pool_rh_cdn for Red Hat, used to subscribe at a Red Hat CDN
pool.

Signed-off-by: Emilien Macchi <d605a501dec15c980af71d9dfebf4b595ab6da1f@enovance.com>

lebauce/edeploy,redhat-cip/edeploy,lebauce/edeploy,lebauce/edeploy,enovance/edeploy,enovance/edeploy,redhat-cip/edeploy,enovance/edeploy,redhat-cip/edeploy,redhat-cip/edeploy,enovance/edeploy,lebauce/edeploy