This extension is currently not used and it is not aligned with
the error handling on async VM_BIND. Let's remove it and along with
that, since it was the only extension for the vm_create, remove VM
extension entirely.

v2: rebase on top of the removal of drm_xe_ext_exec_queue_set_property

Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>