drm/xe: Reinstate pipelined fence enable_signaling

With the GPUVA conversion, the xe_bo::vmas member became replaced with
drm_gem_object::gpuva.list, however there was a couple of usage instances
left using the old member. Most notably the pipelined fence
enable_signaling.

Remove the xe_bo::vmas member completely, fix usage instances and
also enable this pipelined fence enable_signaling even for faulting
VM:s since we actually wait for bind fences to complete.

v2:
- Rebase.
v3:
- Fix display code build error.

Cc: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230915172606.14436-1-thomas.hellstrom@linux.intel.com