Clarify dependency of storage mgmt related commands to machine generation

[andy-maier]

Dependencies:

• hba command group is z13 and earlier
• storagegroup, storagevolume, and vstorageresource command groups are z14 and later

[andy-maier]

It turns out that for the storagegroup, storagevolume, and vstorageresource command groups, the existing statement was sufficient.

For HBAs though, an according statement needed to be added.