packaging: spec: Move R: ovirt-engine-cli to main

The ovirt-engine-cli is not required by the all in one plugin:
moved to the main package.
Also use %{name} macro instead of ovirt-engine prefix.

Change-Id: I38d94b0ff4bf6031e3d3ae49d4f1b889ccfd3b05
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>