drm/xe: Nuke VM's mapping upon close

Clear root PT entry and invalidate entire VM's address space when
closing the VM. Will prevent the GPU from accessing any of the VM's
memory after closing.

v2:
 - s/vma/vm in kernel doc (CI)
 - Don't nuke migration VM as this occur at driver unload (CI)
v3:
 - Rebase and pull into SVM series (Thomas)
 - Wait for pending binds (Thomas)
v5:
 - Remove xe_gt_tlb_invalidation_fence_fini in error case (Matt Auld)
 - Drop local migration bool (Thomas)
v7:
 - Add drm_dev_enter/exit protecting invalidation (CI, Matt Auld)

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250306012657.3505757-12-matthew.brost@intel.com