* gnu/packages/sdcc.scm (sdcc)[source]: Add snippet to remove bundled non-free
source code.
Add patch to disable use of non-free code in build scripts and compiler and
update documentation to match.
* gnu/packages/patches/sdcc-disable-non-free-code.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
Signed-off-by: Marius Bakke <marius@gnu.org>