virtio-gpu: add venus/vulkan capability We are currently lacking a declared maintainer for the sub-system so while we look for one I'm merging after testing locally. - convert some fprintfs to proper trace events - move timers used by GL devices into GL structures - handle virtio_gpu_virgl_init() failure better - implement unrealize for GL devices - use virgl version numbering to gate features - support context-init feature - don't require udmabuf for virgl only - add virgl resource tracker - allow command submission to be suspended - handle resource blob commands - dynamically handle capabilit sets - add venus context support for passing vulkan