iOS: do not set simulator type before initial setup

The run configuration did try to set the simulator type for devices, and
also before knowing the available simulators.
Make most IosDeviceType initialisations explicit about the device type.

Change-Id: I22b87bf4568e1af0c12b1fb91d3074bf29438db2
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@theqtcompany.com>