drm/xe/vf: Fix VM crash during VF driver release

drm/xe/vf: Fix VM crash during VF driver release

The VF CCS save/restore series (patchwork #149108) has a dependency
on the migration framework. A recent migration update in commit
d65ff1ec8535 ("drm/xe: Split xe_migrate allocation from initialization")
caused a VM crash during XE driver release for iGPU devices.

Oops: general protection fault, probably for non-canonical address
0x6b6b6b6b6b6b6b83: 0000 [#1] SMP NOPTI
RIP: 0010:xe_lrc_ring_head+0x12/0xb0 [xe]
Call Trace:
 xe_sriov_vf_ccs_fini+0x1e/0x40 [xe]
 devm_action_release+0x12/0x30
 release_nodes+0x3a/0x120
 devres_release_all+0x96/0xd0
 device_unbind_cleanup+0x12/0x80
 device_release_driver_internal+0x23a/0x280
 device_release_driver+0x12/0x20
 pci_stop_bus_device+0x69/0x90
 pci_stop_and_remove_bus_device+0x12/0x30
 pci_iov_remove_virtfn+0xbd/0x130
 sriov_disable+0x42/0x100
 pci_disable_sriov+0x34/0x50
 xe_pci_sriov_configure+0xf71/0x1020 [xe]

Update the VF CCS migration initialization sequence to align with the new
migration framework changes, resolving the release-time crash.

Fixes: f3009272ff2e ("drm/xe/vf: Create contexts for CCS read write")
Signed-off-by: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Piotr Piórkowski <piotr.piorkowski@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250729120720.13990-1-satyanarayana.k.v.p@intel.com