runc currently only support Linux platform, and since we dont intend to expose
the support to other platform, removing all other platforms placeholder code.
`libcontainer/configs` still being used in
https://github.com/moby/moby/blob/master/daemon/daemon_windows.go so
keeping it for now.
After this, we probably should also rename files to drop linux suffices
if possible.
Signed-off-by: Daniel Dao <dqminh89@gmail.com>
runc is not supported on FreeBSD, so remove all FreeBSD specific bits.
As suggested by @crosbymichael in #1653
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>