[iec] view: Hide downstream projects

IEC Jenkins project view is getting cluttered with all the downstream
static project jobs (e.g. deploy, destroy, install-<usecase>).

Filter only parent jobs (e.g. iec-compass-virtual-ubuntu1604-master),
which offer the best high-level visibility of the overall job status.

Change-Id: I26490baaf0e6c2dc294432804a1f7ba033e9ab6b
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
Signed-off-by: Eric Ball <eball@linuxfoundation.org>