Revert "arm: remove fslsdma from GENERIC"

The firmware was already in the tree when I did this commit, and I
missed the message. The bug was obsolete.

This reverts commit 9e3761d126c5c019d6c935e83989928eb1a0e76e.

The commit was f219c053852d82acb9852cd735c815ba315f416d in stable/13.

PR: 237466
Sponsored by: Netflix

(cherry picked from commit e94f1a0a37fdd3252201aaa5a94f46da7f8e740e)