* nongnu/packages/linux.scm (broadcom-sta-x86_64-source)[patches]: Use
patch.
* nongnu/packages/patches/broadcom-sta-linux-5.9.patch: New patch from
Arch Linux (without already applied hunks).
Closes https://gitlab.com/nonguix/nonguix/-/merge_requests/55.
Signed-off-by: Jonathan Brielmaier <jonathan.brielmaier@web.de>