Dimm memory size support

This commit will calculate the memory size for Dimm and
populate the value with property MemorySizeinKB on dbus.

Test- Tested on simics 2s2u

Set the property with dummy value-

root@rain71bmc:/tmp#  busctl introspect  xyz.openbmc_project.Inventory.Manager  /xyz/openbmc_project/inventory/system/chassis/motherboard/dimm0| grep -e MemorySizeInKB -e  Present -e PrettyName -e Model  -e PartNumber  -e SerialNumber
.Model                                                property  s         "327A"                                   emits-change writable
.PartNumber                                           property  s         "78P6574"                                emits-change writable
.SerialNumber                                         property  s         "YH301T01P00G"                           emits-change writable
.SparePartNumber                                      property  s         ""                                       emits-change writable
.SubModel                                             property  s         ""                                       emits-change writable
.Present                                              property  b         true                                     emits-change writable
.PrettyName                                           property  s         "Memory DIMM"                            emits-change writable
.MemorySizeInKB                                       property  u         33554432                                 emits-change writable
root@rain71bmc:/tmp#

Signed-off-by: Alpana Kumari <alpankum@in.ibm.com>
Change-Id: I70e5bc3f538379f9891ae0ede6cdf09a585520a4
diff --git a/vpd-parser/memory_vpd_parser.hpp b/vpd-parser/memory_vpd_parser.hpp
index 27efafe..cbd44bb 100644
--- a/vpd-parser/memory_vpd_parser.hpp
+++ b/vpd-parser/memory_vpd_parser.hpp
@@ -58,6 +58,14 @@
      */
     kwdVpdMap readKeywords(Binary::const_iterator iterator);
 
+    /**
+     * @brief This function calculates dimm size from DIMM VPD
+     *
+     * @param[in] iterator - iterator to buffer containing VPD
+     * @return calculated data or 0 in case of any error.
+     */
+    auto getDimmSize(Binary::const_iterator iterator);
+
     // vdp file to be parsed
     const Binary& memVpd;
 };