Support building Qbs for host platforms only
Support building Qbs for host platforms only

With this change we don't need a separate Module class in Coin for
Qbs to exclude cross-compilations.

Change-Id: I92e26b668615aeea1cba7fd0ff05d58387c058ee
Reviewed-by: Jake Petroules <2d627e1cecd5435752fa500bacbe05f7cc90c369@qt.io>

qt-labs/qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qt-labs/qbs