[WDF] Add Windows Driver Framework files

Takern from Microsoft GitHub repo:
d9c6040fe9

Licensed under MIT

sdk/lib/drivers/wdf/shared/inc/private/um/fxinterruptum.hpp

@@ -0,0 +1,44 @@
+/*++
+
+Copyright (c) Microsoft Corporation
+
+Module Name:
+
+    FxInterruptUm.hpp
+
+Abstract:
+
+    This module implements a frameworks managed interrupt object
+
+Author:
+
+
+
+Environment:
+
+    User mode only
+
+Revision History:
+
+
+
+--*/
+#ifndef _FXINTERRUPTUM_H_
+#define _FXINTERRUPTUM_H_
+
+#include "FxInterrupt.hpp"
+
+__inline
+struct _KINTERRUPT*
+FxInterrupt::GetInterruptPtr(
+    VOID
+    )
+{
+    //
+    // m_Interrupt is always NULL in UMDF.
+    //
+    return NULL;
+}
+
+#endif // _FXINTERRUPTUM_H_
+