fix deb packaging without west
see https://docs.zephyrproject.org/latest/develop/west/without-west.html
one main part is the hal_nxp submodule that we need to add. I created https://source.puri.sm/Librem5/hal_nxp so that we have a copy ourselves. But: look at CI (or build yourself) and see how the build is failing. I hacked that change to hal_nxp together, that simply "fixes" the build: hal_nxp!1 (merged) That's the next step here. After changing the submodule commit to that one, the build should succeed.