Added comments to the opendaylight-inventory.yang file to help describe
the purpose of the various fields

Change-Id: I1e368b94c9b0c030bb8f7d266019fdeaa97abc80
Signed-off-by: Devin Avery <devin.avery@brocade.com>
Merge "Added comments to the opendaylight-inventory.yang file to help describe the purpose of the various fields"