Add State information for PCIeDevice

This commit is to add state information according to the Redfish
PCIeDevice schema. Default state is "Enabled".
ref: https://redfish.dmtf.org/schemas/v1/PCIeDevice.v1_9_0.json

Tested: Validator passed

'''
 curl -k https://$bmc/redfish/v1/Systems/system/PCIeDevices/pcie_card8


{
  "@odata.id": "/redfish/v1/Systems/system/PCIeDevices/pcie_card8",
  "@odata.type": "#PCIeDevice.v1_9_0.PCIeDevice",
  "Id": "pcie_card8",
  "Manufacturer": "",
  "Model": "6B87",
  "Name": "PCIe Device",
  "PCIeFunctions": {
    "@odata.id": "/redfish/v1/Systems/system/PCIeDevices/pcie_card8/PCIeFunctions"
  },
  "PCIeInterface": {
    "LanesInUse": -1
  },
  "PartNumber": "03FL194",
  "SerialNumber": "Y131UF09S00J",
  "Slot": {
    "Location": {
      "PartLocation": {
        "ServiceLabel": "U78DB.ND0.WZS0018-P0-C8"
      }
    }
  },
  "SparePartNumber": "03FL195",
  "Status": {
    "Health": "OK",
    "State": "Enabled"
  }
}
'''

Change-Id: Ibee01345c81c2e824fc2387c4f27e421b3f4c507
Signed-off-by: Lakshmi Yadlapati <lakshmiy@us.ibm.com>