output/wasapi: move to separate directory

src/output/plugins/meson.build

@@ -136,7 +136,7 @@ endif
 output_features.set('ENABLE_WASAPI_OUTPUT', is_windows)
 if is_windows
   output_plugins_sources += [
-    'WasapiOutputPlugin.cxx',
+    'wasapi/WasapiOutputPlugin.cxx',
   ]
   wasapi_dep = [
     c_compiler.find_library('ksuser', required: true),

src/output/plugins/wasapi/WasapiOutputPlugin.hxx

@@ -22,7 +22,7 @@
 
 #include "output/Features.h"
 
-#include "../OutputAPI.hxx"
+#include "output/OutputAPI.hxx"
 #include "util/Compiler.h"
 #include "win32/ComPtr.hxx"