Host: Remove unnecessary functions

Remove Host_RefreshDSPDebuggerWindow (which hasn't done anything since
DolphinWX was removed in 44b22c90) and DSP::Host::UpdateDebugger (which
only called Host_RefreshDSPDebuggerWindow).

Source/Android/jni/MainAndroid.cpp

@@ -110,10 +110,6 @@ void Host_PPCBreakpointsChanged()
 {
 }
 
-void Host_RefreshDSPDebuggerWindow()
-{
-}
-
 bool Host_UIBlocksControllerState()
 {
   return false;