iommu: Remove comment of dev_has_feat in struct doc

dev_has_feat has been removed from iommu_ops in commit
309c56e8 ("iommu: remove the unused dev_has_feat method"),
remove its description in the struct doc.
Signed-off-by: Yuan Can <yuancan@huawei.com>
Link: https://lore.kernel.org/r/20220815013339.2552-1-yuancan@huawei.comSigned-off-by: Joerg Roedel <jroedel@suse.de>

include/linux/iommu.h

@@ -212,7 +212,7 @@ struct iommu_iotlb_gather {
  * @of_xlate: add OF master IDs to iommu grouping
  * @is_attach_deferred: Check if domain attach should be deferred from iommu
  *                      driver init to device driver init (default no)
- * @dev_has/enable/disable_feat: per device entries to check/enable/disable
+ * @dev_enable/disable_feat: per device entries to enable/disable
  *                               iommu specific features.
  * @sva_bind: Bind process address space to device
  * @sva_unbind: Unbind process address space from device