Allows users to submit options similar to the `mount` command when
creating a volume with the `local` volume driver.
For example:
```go
$ docker volume create -d local --opt type=nfs --opt device=myNfsServer:/data --opt o=noatime,nosuid
```
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Upstream-commit: b05b2370757d7143d761e5e6abb8c0f9b009f737
Component: engine
8bbce28a1d