iommu/vt-d: Remove scalable mode context entry setup from attach_dev

The scalable mode context entry is now setup in the probe_device path,
eliminating the need to configure it in the attach_dev path. Removes the
redundant code from the attach_dev path to avoid dead code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20240305013305.204605-5-baolu.lu@linux.intel.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>