edgeos: Add dev-util/rt-tests package

Adding just the cyclictest binary

Copied the initial ebuild from
https://packages.gentoo.org/packages/dev-util/rt-tests upstream. Changed
to EAPI 7, and older python versions. Changes to the src_compile and
src_install steps to only compile and install the cyclictest binary that
we need.

This should be submitted _after_ cl/531631522 so it doesn't break the build

BUG=b/282014097
TEST=verified in qemu that the binary is installed
TEST=verified manually that google3 compiles with cl/531631522
RELEASE_NOTE=add rt-tests package

Change-Id: If33c6ceeb739f9fa3a1eecd95153ca23592bbf5e
Reviewed-on: https://cos-review.googlesource.com/c/cos/overlays/board-overlays/+/49309
Reviewed-by: Joshua Emele <jemele@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
7 files changed