Remove debug symbols and dynamic debug support from Linux. This reduces
our resulting bzImage by 100K.
This should help when size becomes even more limited, see #562
This changes Heads' bootscript for the x230 to gui-init and adds config
options needed for it. The config is very similar to the librem13v2 config.
My comparison of startup-time from a power-button press shows 2.5 seconds
more with these changes applied.
That said, the experience is smooth, the GUI is beautiful and easier to use
than the shell and text menu, especially during setup. That's what we
buy with startup time here.