popn: implement bi3a-hook (bio3) (#626)

## Link to GitHub Issue or related Pull Request, if one exists
#618 

## Description of change
Turns out running this with bi2x doesn't process buttons properly, so we
have to use bi3a.

## Testing
Seems playable now.

src/spice2x/CMakeLists.txt

@@ -383,7 +383,7 @@ set(SOURCE_FILES ${SOURCE_FILES}
         games/shared/twtouch.cpp
         games/popn/popn.cpp
         games/popn/io.cpp
-        games/popn/bi2x_hook.cpp
+        games/popn/bi3a_hook.cpp
         games/bbc/bbc.cpp
         games/bbc/io.cpp
         games/hpm/hpm.cpp