Enable etcd-wrapper on arm64.

[glevand]

Also adds missing ebuild metadata.

Same ebuild structure as #2511 (Reenable flannel on arm64).

To work as-is on arm64 the etcd-wrapper needs etcd-io/etcd#7714 and an arm64 release to quay.io/coreos/etcd.

For testing, a systemd drop-in /etc/systemd/system/etcd-member.service.d/local.conf with something like this should work:

[Service]
Environment="ETCD_UNSUPPORTED_ARCH=arm64"
Environment="ETCD_IMAGE=docker://quay.io/glevand/etcd:v3.1.6-arm64"
Environment="RKT_RUN_ARGS=--uuid-file-save=/var/lib/coreos/etcd-member-wrapper.uuid --insecure-options=image"

[crawford]

Seems fine. We'll need those ARM images published first. I'll talk with the etcd team about that.

[glevand]

@crawford Did you want to rename etcd-wrapper-0.0.4.ebuild to etcd-wrapper-3.0.10.ebuild so the ebuild package version matches the etcd release? Then we can use ${PV} in the ebuild, and it makes it easier to know which etcd version the package uses.

I can do that in this PR, or make another.

[crawford]

Seems like a reasonable idea. I'd be fine with it in a separate commit in this PR.

[glevand]

Added patch etcd-wrapper: Change ebuild version to etcd release.

[glevand]

Rebased to lastest.
Dropped patch etcd-wrapper: Change ebuild version to etcd release, which became duplicated in #2549 (app-admin/etcd-wrapper: bump to etcd 3.1.6).

[dm0-]

Sorry I missed this. A few minor tweaks, and this looks good.

[dm0-]

The coreos ebuild revision number should probably be bumped for this. (The symlink in the same directory.) Maybe the coreos-base/coreos changes could be in their own commit.

[dm0-]

Since the ebuild has the same version now, maybe make this value "v${PV}" so updates only require a rename with no edits.

[glevand]

Used ${PV} for etcd release tag.
Moved coreos-base/coreos changes to separate patch and bumped ebuild version.