[X11] Qxcbconnection fails to build with Xinput 2.0

Qxcbconnection fails to build with Xinput 2.0 since an ifdef is missing from qtbase/src/plugins/platforms/xcb/qxcbconnection_xi.cpp:1029.
QXcbConnection::isTouchScreen() needs to be wrapped with #ifdef XCB_USE_XINPUT22 as it is done in the header.

#ifdef XCB_USE_XINPUT22 
bool QXcbConnection::isTouchScreen(int id) const 
{ 
auto device = m_touchDevices.value(id); 
return device && device->qtTouchDevice 
&& device->qtTouchDevice->type() == 
QTouchDevice::TouchScreen; 
} 
#endif