Hey guys. So I was playing Pokemon Soul Silver on my DeSmuMe emulator and I decided to try looking for a way to speed the game up. And I found one. I think that the defaut key for speeding up is the Tab button, but if it is not there is a way to change it. Just go to Config -> Hotkey Config and change the fast forward button to whatever you want.
Here are some screenshots for those of you who can't understand what I'm saying:
Hope I helped!