Simplify building of simulator based code

There is no need for the CONFIG+=simulator logic anymore.
qtHaveModule() is an automatic way of doing the same.

Change-Id: Ibe87abb93e036a82fae3a752d9886c58ccebeec1
Reviewed-by: Rainer Keller <rainer.keller@digia.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>