VisualC: add DSU DSU joystick driver sources

Author: danprice142

VisualC/SDL/SDL.vcxproj

@@ -389,6 +389,8 @@
     <ClInclude Include="..\..\src\joystick\SDL_steam_virtual_gamepad.h" />
     <ClInclude Include="..\..\src\joystick\SDL_sysjoystick.h" />
     <ClInclude Include="..\..\src\joystick\usb_ids.h" />
+    <ClInclude Include="..\..\src\joystick\dsu\SDL_dsuprotocol.h" />
+    <ClInclude Include="..\..\src\joystick\dsu\SDL_dsujoystick_c.h" />
     <ClInclude Include="..\..\src\joystick\virtual\SDL_virtualjoystick_c.h" />
     <ClInclude Include="..\..\src\joystick\windows\SDL_dinputjoystick_c.h" />
     <ClInclude Include="..\..\src\joystick\windows\SDL_rawinputjoystick_c.h" />
@@ -637,6 +639,8 @@
     <ClCompile Include="..\..\src\joystick\SDL_gamepad.c" />
     <ClCompile Include="..\..\src\joystick\SDL_joystick.c" />
     <ClCompile Include="..\..\src\joystick\SDL_steam_virtual_gamepad.c" />
+    <ClCompile Include="..\..\src\joystick\dsu\SDL_dsujoystick.c" />
+    <ClCompile Include="..\..\src\joystick\dsu\SDL_dsujoystick_driver.c" />
     <ClCompile Include="..\..\src\joystick\virtual\SDL_virtualjoystick.c" />
     <ClCompile Include="..\..\src\joystick\windows\SDL_dinputjoystick.c" />
     <ClCompile Include="..\..\src\joystick\windows\SDL_rawinputjoystick.c" />