loveplus: enable cam access (#318)

## Link to GitHub Issue, if one exists
#316 
(this does not fix the issue!)

## Description of change
Add an option to omit `-noCamera` option. Doing so allows the game to
boot and search for a compatible camera using KS API, but will likely
fail since we don't know what cameras are compatible. You end up with a
camera error during boot, which can be ignored by flipping a switch in
the test menu to disable the camera.

No hooks are currently done to make the camera work!

## Testing
Tested to see that turning this on triggers the camera error. No known
camera at the moment.

src/spice2x/games/loveplus/loveplus.h

@@ -4,6 +4,8 @@
 
 namespace games::loveplus {
 
+    extern bool CAMERA_ENABLE;
+
     // touch stuff
     void touch_update();