Add the custom u-boot and kernel for iMX8. Also the kernel must
be uncompressed for u-boot booti to work.

The image build will still pick up 4.15 until we tested 4.16 some more.

Now that we build different boards print out some variables upfront
so builds can be identified quicker.

Make variables can be overridden on the comand line without any
additional fuzz.

We just use the one shipped by Debian so we don't have to maintain
more stuff on the remote end.

we moving configuraton to conf/ I forgot to reflect that in
the Makefile

so we can test settings, goa, etc.

so we can fit more tools into the image but still use a 4G card

So nm-connection-editor can be used to create WWAN connections