kernel-2.eclass: add crosscompile_opts_headers-only to IUSE

Cherry-pick upstream Gentoo change to kernel-2.eclass from:
https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=0639f1e3a412852299e360b30d77d19fd0a8b679

Original CL description:
author	Mike Gilbert <floppym@gentoo.org>	2016-08-02 22:03:21 -0400
committer	Mike Gilbert <floppym@gentoo.org>	2016-08-02 22:05:13 -0400
commit	0639f1e3a412852299e360b30d77d19fd0a8b679 (patch)
tree	6609f43a21a8aeb29c09aa2f02b6751e2570b051

kernel-2.eclass: add crosscompile_opts_headers-only to IUSE
Fixes installation of cross headers for ebuilds using EAPI 5+.

BUG=chromium:822807
TEST=sudo emerge cross-i686-pc-linux-gnu/linux-headers works.

Change-Id: Id26f98807fcc478045104b7873c4d8022a2d9e24
Reviewed-on: https://chromium-review.googlesource.com/967011
Commit-Ready: Manoj Gupta <manojgupta@chromium.org>
Tested-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Rahul Chaudhry <rahulchaudhry@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed