Modifies mkinitfs *.files files to expect firmware under `/usr/lib/` and cleans up firmware installs missed by the initial migration. https://gitlab.postmarketos.org/postmarketOS/pmaports/-/work_items/4354 Signed-off-by: Aster Boese <asterboese@mailbox.org> Part-of: <https://gitlab.postmarketos.org/postmarketOS/pmaports/-/merge_requests/8450>