Ensure doc and examples do not end up in Qt5 binary packages

We'll start using single doc component in installer so make sure
examples or doc directories do not exist in binary packages.

Also archive the doc package in correct place.

Change-Id: I018a286b136ece1b0fad43d54a7aa96a794f3283
Reviewed-by: Antti Kokko <antti.kokko@digia.com>