pc: fix certain controller bindings not working (#368)

## Link to GitHub Issue, if one exists
Fixes #364 

## Description of change
The game attempts to hook raw input, but raw input API can only be used
by one window per process. Hook `RegisterRawInputDevices` and prevent
the game from registration for raw input notifications.

## Testing
Tested that HID keyboard works with `Bind` option.

src/spice2x/rawinput/rawinput.h

@@ -54,7 +54,6 @@ namespace rawinput {
 
         HotplugManager *hotplug;
         std::vector<Device> devices;
-        HWND input_hwnd = nullptr;
         WNDCLASSEX input_hwnd_class {};
         std::thread *input_thread = nullptr;
         std::thread *flush_thread = nullptr;
@@ -91,6 +90,8 @@ namespace rawinput {
 
     public:
 
+        HWND input_hwnd = nullptr;
+
         RawInputManager();
         ~RawInputManager();