PNOR: Add logic to handle the case where ubi volume creation failure

- Combine the service files that creates the UBI volumes
- Add "OnFailure" to service files that creates UBI volumes
  in order to clean up any ubi voumes or mount points that
  were created during the activation.
- Part of the change required for openbmc/openbmc#1616.

Change-Id: Ibe316c810e797b256c141c5ea6583970da5e57b8
Signed-off-by: Saqib Khan <khansa@us.ibm.com>
3 files changed