Deprecate TSM Backup driver

TSM Driver seems to be broken for a while [1] and is not supported
anymore.

[1] https://review.opendev.org/#/q/Ie67d919f8f59572268f1f07946fb2d2f14a851f1

Change-Id: I33bbe4f50040096b71bb1540b87dc10d575b46b4

cinder/backup/drivers/tsm.py

@@ -32,6 +32,7 @@ import stat
 from oslo_concurrency import processutils
 from oslo_config import cfg
 from oslo_log import log as logging
+from oslo_log import versionutils
 
 from cinder.backup import driver
 from cinder import exception
@@ -275,6 +276,11 @@ class TSMBackupDriver(driver.BackupDriver):
         return tsm_opts
 
     def check_for_setup_error(self):
+        versionutils.report_deprecated_feature(
+            LOG,
+            "Cinder TSM Backup Driver is deprecated and will be removed "
+            "in Wallaby release. Please, migrate you backups to a supported "
+            "backend.")
         required_flags = ['backup_share']
         for flag in required_flags:
             val = getattr(CONF, flag, None)

releasenotes/notes/deprecate-tsm-backup-driver-8be0c78ec1a9d6dc.yaml

@@ -0,0 +1,5 @@
+---
+deprecations:
+  - |
+    Cinder TSM Backup Driver is deprecated and will be removed in Wallaby
+    release.