API to read IM value from persisted location

This commit implements API to read IM value from PIM persisted
location.

Change-Id: I9cd4f6ed9ded2dd4f42c65902509f7bea9e15849
Signed-off-by: Anupama B R <anupama.b.r1@ibm.com>
diff --git a/vpd-manager/include/constants.hpp b/vpd-manager/include/constants.hpp
index f71b18e..cddc8ab 100644
--- a/vpd-manager/include/constants.hpp
+++ b/vpd-manager/include/constants.hpp
@@ -121,6 +121,8 @@
 constexpr auto systemInvPath = "/xyz/openbmc_project/inventory/system";
 constexpr auto pimPath = "/xyz/openbmc_project/inventory";
 constexpr auto pimIntf = "xyz.openbmc_project.Inventory.Manager";
+constexpr auto pimPersistVsbpPath =
+    "/var/lib/phosphor-inventory-manager/xyz/openbmc_project/inventory/system/chassis/motherboard/com.ibm.ipzvpd.VSBP";
 constexpr auto ipzVpdInf = "com.ibm.ipzvpd.";
 constexpr auto kwdVpdInf = "com.ibm.ipzvpd.VINI";
 constexpr auto vsysInf = "com.ibm.ipzvpd.VSYS";