drm/xe: Drop rebind argument from xe_pt_prepare_bind

This is unused, drop it.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Oak Zeng <oak.zeng@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240201184844.2317004-1-matthew.brost@intel.com