Move containerd init file from init package to containerd package

Otherwise it gets out of sync, and it makes little sense it being in
`init` now anyway.

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

pkg/containerd/Dockerfile

@@ -33,3 +33,4 @@ WORKDIR /
 COPY --from=alpine /usr/bin/containerd /usr/bin/ctr /usr/bin/dist /usr/bin/containerd-shim /go/bin/service /usr/bin/
 COPY --from=alpine /etc/containerd/config.toml /etc/containerd/
 COPY --from=alpine /usr/share/zoneinfo/UTC /etc/localtime
+COPY etc etc/

pkg/containerd/Makefile

@@ -1,4 +1,5 @@
 IMAGE=containerd
 NETWORK=1
+DEPS=$(wildcard etc/init.d/*)
 
 include ../package.mk