Remove -fw and -l command line arguments

These arguments were nonsensical, as they would lead to every single Qt
module linking to those libraries. This was probably some left-over from
old times, when Qt was just a single library.

Change-Id: I0343a6df270fd0d2efa5333ba4e457670f5d0910
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>