drm/xe/uapi: Remove sync binds

Remove concept of async vs sync VM bind queues, rather make all binds
async.

The following bits have dropped from the uAPI:
DRM_XE_ENGINE_CLASS_VM_BIND_ASYNC
DRM_XE_ENGINE_CLASS_VM_BIND_SYNC
DRM_XE_VM_CREATE_FLAG_ASYNC_DEFAULT
DRM_XE_VM_BIND_FLAG_ASYNC

To implement sync binds the UMD is expected to use the out-fence
interface.

v2: Send correct version
v3: Drop drm_xe_syncs

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Francois Dugast <francois.dugast@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Acked-by: José Roberto de Souza <jose.souza@intel.com>
Acked-by: Mateusz Naklicki <mateusz.naklicki@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>