packaging: setup: validate unicast MAC address

Change-Id: I6af3523bff99d153691996152f39b7d4750eeaf5
Bug-Url: https://bugzilla.redhat.com/1116785
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>
(cherry picked from commit 6c1b4046ea12306dc8dd556f0ca41f70defdbfe6)