Use Utils::Port where possible

This solves the ambiguity between 0 and -1 being the "invalid" port.

Change-Id: I3bac11dd4117bb1820fbd58186699925b73df1c5
Reviewed-by: hjk <hjk@theqtcompany.com>

src/plugins/ios/iosdevice.h

@@ -66,7 +66,7 @@ public:
     QString uniqueDeviceID() const;
     IosDevice(const QString &uid);
     QString osVersion() const;
-    quint16 nextPort() const;
+    Utils::Port nextPort() const;
     bool canAutoDetectPorts() const override;
 
     static QString name();