drm/xe: Suspend/resume user access only during system s/r

Enable/Disable user access only during system suspend/resume.
This should not happen during runtime s/r

v2: rebased

Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240823112148.327015-2-vinod.govindapillai@intel.com