Beside some refactorings that don't affect coreboot, this contains bd0ed91 (Makefile: Revise support for generated sources) that fixes an issue with upcoming libgfxinit configuration changes. Change-Id: Ib47aeff8f6426ae27ddbc235a954e3bd60029072 Signed-off-by: Nico Huber <nico.huber@secunet.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/32735 Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-by: Patrick Georgi <pgeorgi@google.com> Reviewed-by: Arthur Heymans <arthur@aheymans.xyz> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>