Ref T180, adjusted FSX/P3D includes

* the fix header belongs into fsxcommon (not fsx) dir
* P3D is purely P3D, we do not build a P3D x86 driver

src/plugins/simulator/fsx/simconnectwindows.h

@@ -1,13 +0,0 @@
-// in P3Dv4 the simconnect.h does not include windows.h
-// here we include windows.h first
-
-#ifndef BLACKSIMPLUGIN_FSX_SIMCONNECTWINDOWS_H
-#define BLACKSIMPLUGIN_FSX_SIMCONNECTWINDOWS_H
-
-#ifndef NOMINMAX
-#define NOMINMAX
-#endif
-#include <windows.h>
-#include <SimConnect.h>
-
-#endif // guard