The wl1251 driver in upstream linux kernels expects its firmware files
to live at
ti-connectivity/wl1251-fw.bin
ti-connectivity/wl1251-nvs.bin
and the linux-firmware package uses the same names for these files.
However, our current (older) kernel still expects them to be named
wl1251-fw.bin
wl1251-nvs.bin
and so firmware loading would fail.
RescueOS v1.1 included these files under the older filenames, but we'd
like to use the official (upstream) names. Patch our kernel to match.
Also remove the unnecessary (and now erroneous) firmware check from
setup-wpa-wifi.sh.
Setup buildroot filesystem overlay and move our custom scripts/configs
into it. Setup a post-build script and have it delete files generated
by buildroot that aren't in RescueOS v1.1.
This gets us closer to a buildroot configuration that will automatically
generate RescueOS images. For now, we're using RescueOS v1.1 as a
reference.
