Add stubs for distortion and gargle effects in dsdmo.
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55978
Currently Distortion effect is used by games like Fallout 3 and Gargle effect AFAIK is only in the DXSDK 9 demos.
-- v3: dsdmo: Add Gargle effect stub. dsdmo: Add Distortion effect stub.