builder/parallels: Set positions of hdd and cdroms

This to ensure proper booting on some OSs, for example OmniOS.

@JessThrysoee _**Drop my previous commit and try this.**_

It works for me on multiple OS'es and I did a simple test with an usb dvd attached. So hopefully it should work for you too.

@legal90 I'll think it is unfortunate that it's not possible to set _'Default CDROM/DVD'_ with ```prlctl``` since it is a valid value. In general I think that ```prlctl``` has to have the same power as the GUI.