IBM VPD Parser support for both 2U & 4U system

Based on motherboard IM keyword the type of the system is identified
and the corresponding json is linked at the runtime.

Currently 2U system has support for single dasd-backplane
whereas 4U system has support for more than one dasd-backplanes.

Tested on simics.

Change-Id: Ia3eb48661fe565f6286c079a8f87736bb136210a
Signed-off-by: Priyanga Ramasamy <priyanga24@in.ibm.com>
diff --git a/const.hpp b/const.hpp
index c2ff5b3..1ee8c89 100644
--- a/const.hpp
+++ b/const.hpp
@@ -46,6 +46,8 @@
 constexpr uint8_t EXP_LOCATIN_CODE_MIN_LENGTH = 17;
 static constexpr auto SE_KWD_LENGTH = 7;
 static constexpr auto INVALID_NODE_NUMBER = -1;
+static constexpr auto SYSTEM_2U = "50001001";
+static constexpr auto SYSTEM_4U = "50001000";
 
 namespace lengths
 {