PGP Command Line for IBM mainframe is not supplied or supported by Broadcom and never has been.
As per the System Requirements, PGP Command Line is supported on:
PGP Command Line for the IBM i and IBM Z platforms is available directly from Precisely. Please contact:
Dawn Winston
Note too that IBM offers an Encryption Facility for OpenPGP for z/OS. This should be compatible with PGP Command Line running on one of the operating systems that it supports. Please contact IBM for more information and support.
PGP Command Line for IBM Power System - If you need help with this platform, please contact Symantec Encryption support and mention EPG-27028.