Enable WDM/KS support for PortAudio

See #716.

src/portaudio-2-wdmks.patch

@@ -0,0 +1,15 @@
+This file is part of MXE.
+See index.html for further information.
+
+http://music.columbia.edu/pipermail/portaudio/2015-June/016833.html
+
+--- portaudio/src/hostapi/wdmks/pa_win_wdmks.c	2012-12-28 17:54:25.000000000 +0100
++++ portaudio-patched/src/hostapi/wdmks/pa_win_wdmks.c	2015-06-17 14:29:23.695735572 +0200
+@@ -87,7 +87,6 @@
+ #include "pa_win_wdmks.h"
+ 
+ #include <windows.h>
+-#include <winioctl.h>
+ #include <process.h>
+ 
+ #include <math.h>

src/portaudio.mk

@@ -25,7 +25,7 @@ define $(PKG)_BUILD
     cd '$(1)' && ./configure \
         $(MXE_CONFIGURE_OPTS) \
         --with-host_os=mingw \
-        --with-winapi=wmme,directx \
+        --with-winapi=wmme,directx,wdmks \
         --with-dxdir=$(PREFIX)/$(TARGET) \
         ac_cv_path_AR=$(TARGET)-ar \
         $(if $(BUILD_SHARED),\