drm/xe/pf: Create a link between PF and VF devices

drm/xe/pf: Create a link between PF and VF devices

When both PF and VF devices are enabled on the host, they
resume simultaneously during system resume.

However, the PF must finish provisioning the VF before any
VFs can successfully resume.

Establish a parent-child device link between the PF and VF
devices to ensure the correct order of resumption.

V4 -> V5:
- Added missing break in the error condition.
V3 -> V4:
- Made xe_pci_pf_get_vf_dev() as a static function and updated
  input parameter types.
- Updated xe_sriov_warn() to xe_sriov_abort() when VF device
  cannot be found.
V2 -> V3:
- Added function documentation for xe_pci_pf_get_vf_dev().
- Added assertion if not called from PF.
V1 -> V2:
- Added a helper function to get VF pci_dev.
- Updated xe_sriov_notice() to xe_sriov_warn() if vf pci_dev
  is not found.

Signed-off-by: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
Cc: Michał Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Piotr Piórkowski <piotr.piorkowski@intel.com>
Reviewed-by: Piotr Piorkowski <piotr.piorkowski@intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250224102807.11065-2-satyanarayana.k.v.p@intel.com