Revert "Only use VDPAU hwaccel API for mpeg container"

Better fix coming

This reverts commit 2502f4a3c45b76684d1d37b9b6d39112c3fffd09.
Do not use VDPAU hwaccel API for mpeg4 videos

FFmpeg 1.2's VDPAU hwaccel is clearly unstable. 24fps mpeg4 in AVI would play at half that rate, cause crashes with nouveau or visual distortion with AMD

Add a "vdpauhwaccel" setting override to completely disable VDPAU hwaccel under all circumstances

Fixes #12162