Libva 2.20.0

• va: drop no longer applicable vaGetDriverNames check
• va: remove unreachable "DRIVER BUG"
• x11/dri2: limit the array handling to avoid out of range access
• va/backend: document the vaGetDriver* APIs
• va/backend: annotate vafool as deprecated
• win32: remove duplicate adapter_luid entry
• va: Added Q416 fourcc (three-plane 16-bit YUV 4:4:4)
• trace: fix minor issue about printf data type and value range
• jpeg: add support for crop and partial decode
• trace: Unlock mutex before return
• trace: Add trace for vaExportSurfaceHandle
• av1: Revise offsets comments for av1 encode
• va: Add new VADecodeErrorType to indicate the reset happended in the driver.
• drm: limit the array size to avoid out of range
• va: fix:set driver number to be zero if vaGetDriverNames failed
• va: fix:don't leak driver names, when override is set
• win32: Only print win32 driver messages in DEBUG builds
• va: Add vendor string on va_TraceInitialize
• va: remove legacy code paths
• drm: remove no longer used helpers
• x11: remove legacy code paths
• x11: allow disabling DRI3 via LIBVA_DRI3_DISABLE env var
• x11: implement vaGetDriverNames
• va/x11/va_nvctrl: remove some dead code
• va/x11/va_fglrx: remove some dead code
• va: optimize code of getting driver name for all protocols/os(wayland,x11,drm,win32,android)