util: change coreboot to lowercase

The word 'coreboot' should always be written in lowercase, even at the
start of a sentence.

Change-Id: I0a024d82d331c0794fe087e440b4e1924129a13c
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/20030
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
6 files changed