Clarify description of LanesInUse description

The values of LanesInUse are clarified
- "0" as unused
- "maxint" (default) as unknown or unavailable

Change-Id: I6831d3a6f09253482a8d451f86b8631612f6384e
Signed-off-by: Myung Bae <myungbae@us.ibm.com>
diff --git a/yaml/xyz/openbmc_project/Inventory/Item/PCIeDevice.interface.yaml b/yaml/xyz/openbmc_project/Inventory/Item/PCIeDevice.interface.yaml
index 71152ad..8826a9d 100644
--- a/yaml/xyz/openbmc_project/Inventory/Item/PCIeDevice.interface.yaml
+++ b/yaml/xyz/openbmc_project/Inventory/Item/PCIeDevice.interface.yaml
@@ -296,7 +296,7 @@
           The number of PCIe lanes in use by this device. Default value of
           maxint is to accommodate the situation where the value of this
           property is not known due to some unknown reason, like hardware
-          failure or link down.
+          failure. The value of 0 indicates that the link is not active.
 
 associations:
     - name: upstream_pcie_slot