Fix changelog file generation in make system

[Sergey Kulanov]

We need to check/fix logic for changelog file generation

https://github.com/stackforge/fuel-main/blob/master/mirror/module.mk#L21

After adding deb packages build we have changes in targets dependencies and now we generate changelog for already modified deb local mirror.

So we need to decide, which information changelog file should contain:
1) Just packages from "upstream" mirrors (rpm, deb)
2) Just packages from "upstream" mirrors (rpm, deb)+ those packages that were built during make iso

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/184116

[Sergey Otpuschennikov (sotpuschennikov)]

This patch affects the build of mirrors, because the target changes.
After merge need change build mirrors script: https://review.fuel-infra.org/#/c/6816/

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/211742

[OpenStack Infra (hudson-openstack)]

Change abandoned by Sergey Kulanov (<email address hidden>) on branch: master
Review: https://review.openstack.org/184116
Reason: Won't fix

[OpenStack Infra (hudson-openstack)]

Change abandoned by Sergey Kulanov (<email address hidden>) on branch: master
Review: https://review.openstack.org/211742
Reason: Won't fix

[Fuel Devops McRobotson (fuel-devops-robot)]

Change abandoned by Sergey Otpuschennikov <email address hidden> on branch: master
Review: https://review.fuel-infra.org/6816