core: prevent selection of "cpu pinning" and "manual migration"

Cpu pinning and migration (manual or automat) should be mutually
excluded. Currently only the use of automatic migration is checked. this
patch adds a check for manual migration as well.

Change-Id: I906ae6c46e7ce520fedc172be1601b4c61735bf8
Bug-Url: https://bugzilla.redhat.com/926962
Signed-off-by: Ofri Masad <omasad@redhat.com>