Log PEL if System type DTB not supported

System boots up with respective dtb for that system type,
which is based on HW and IM keyword of system VPD.
If any new value comes for these keywords, that needs to be supported
in vpd-parser, otherwise it will log PEL and exit.
This commit is dependent on PDI change-
https://gerrit.openbmc-project.xyz/c/openbmc/phosphor-dbus-interfaces/+/49025

Signed-off-by: Alpana Kumari <alpankum@in.ibm.com>
Change-Id: I66e43a8aab38511bfaa59641556ea9e58b3f87e2
diff --git a/const.hpp b/const.hpp
index ef0793e..cf50452 100644
--- a/const.hpp
+++ b/const.hpp
@@ -88,6 +88,8 @@
 constexpr auto errIntfForEccCheckFail = "com.ibm.VPD.Error.EccCheckFailed";
 constexpr auto errIntfForJsonFailure = "com.ibm.VPD.Error.InvalidJson";
 constexpr auto errIntfForBusFailure = "com.ibm.VPD.Error.DbusFailure";
+constexpr auto errIntfForInvalidSystemType =
+    "com.ibm.VPD.Error.UnknownSytemType";
 constexpr auto motherBoardInterface =
     "xyz.openbmc_project.Inventory.Item.Board.Motherboard";
 constexpr auto systemVpdFilePath = "/sys/bus/i2c/drivers/at24/8-0050/eeprom";