Draft: drm/msm: sparse / "VM_BIND" support

Conversion to DRM GPU VA Manager, and adding support for Vulkan Sparse Memory in the form of:

1. A new VM_BIND submitqueue type for executing VM MSM_SUBMIT_BO_OP_MAP/MAP_NULL/UNMAP commands
2. Extending the SUBMIT ioctl to allow submitting batches of one or more MAP/MAP_NULL/UNMAP commands to a VM_BIND submitqueue

The UABI takes a slightly different approach from what other drivers have done, and what would make sense if starting from a clean sheet, ie separate VM_BIND and EXEC ioctls. But since we have to maintain support for the existing SUBMIT ioctl, and because the fence, syncobj, and BO pinning is largely the same between legacy "BO-table" style SUBMIT ioctls, and new-style VM updates submitted to a VM_BIND submitqueue, I chose to go the route of extending the existing SUBMIT ioctl rather than adding a new ioctl.

I also did not implement support for synchronous VM_BIND commands. Since userspace could just immediately wait for the SUBMIT to complete, I don't think we need this extra complexity in the kernel. Synchronous/immediate VM_BIND operations could be implemented with a 2nd VM_BIND submitqueue.

The corresponding mesa MR: mesa/mesa!32533

This MR can be found in patch form if you prefer: https://patchwork.freedesktop.org/series/142263/