drm/xe/bo: Use scope-based runtime PM
Use scope-based runtime power management in the BO code for consistency
with other parts of the driver.
v2:
- Drop unnecessary 'ret' variable. (Gustavo)
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patch.msgid.link/20251118164338.3572146-50-matthew.d.roper@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>