xsel: add package from upstream

Added x11-misc/xsel to version 1.2.0-r1 on amd64

BUG=none
TEST=emerge xsel && xsel -i --clipboard <<<"Hello Wrld"

Change-Id: I5e2413e1caf1d20b49cbddb8afb5d749361aa4f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/2122772
Tested-by: Raul E Rangel <rrangel@chromium.org>
Commit-Queue: Benjamin Gordon <bmgordon@chromium.org>
Auto-Submit: Raul E Rangel <rrangel@chromium.org>
Reviewed-by: Benjamin Gordon <bmgordon@chromium.org>
4 files changed