BuildDate encoding support for FRUs

This commit and vpd-json commit together enables the encoding for
BuildDate and set Present state true for all the FRUs.

Test:

[[0;1;39mxyz.openbmc_project.Inventory.Decorator.Asset[[0m interface -         -
.BuildDate                                    property  s         "2019-08-26 11:00"

[[0;1;39mxyz.openbmc_project.Inventory.Item                  [[0m interface -
.Present                                             property  b         true

Change-Id: I6d2f07477b0079c1df370908558b2ab0f17a4212
Signed-off-by: Alpana Kumari <alpankum@in.ibm.com>
diff --git a/defines.hpp b/defines.hpp
index 25303d3..0d493ac 100644
--- a/defines.hpp
+++ b/defines.hpp
@@ -152,5 +152,10 @@
     ETHERNET1
 };
 
+static constexpr auto BD_YEAR_END = 4;
+static constexpr auto BD_MONTH_END = 7;
+static constexpr auto BD_DAY_END = 10;
+static constexpr auto BD_HOUR_END = 13;
+
 } // namespace vpd
 } // namespace openpower