Move the usage instructions from their ad-hoc place in Kconfig.name to
the Documentation directory, and expand them a bit.
Change-Id: Id6c7bbca40a21ecba00cab736af2f2662a985106
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-on: https://review.coreboot.org/28874
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Philipp Hug <philipp@hug.cx>
Jonathan Neuschäfer