Common file to hold all constant values

This commit introduces a const.hpp file to hold all the
constants related to the openpower vpd repository.
All new and ongoing implementations can make use of this
file to declare or reuse constants.

Signed-off-by: Sunny Srivastava <sunnsr25@in.ibm.com>
Change-Id: Ib93c1c264dc8c69198140d63318e7e132d33fb13
diff --git a/impl.hpp b/impl.hpp
index 8d3b59e..a6ac39d 100644
--- a/impl.hpp
+++ b/impl.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "const.hpp"
 #include "store.hpp"
 
 #include <cstddef>
@@ -12,7 +13,6 @@
 {
 namespace keyword
 {
-
 /** @brief Encoding scheme of a VPD keyword's data */
 enum class Encoding
 {
@@ -35,22 +35,6 @@
 
 } // namespace internal
 
-namespace
-{
-
-using RecordId = uint8_t;
-using RecordOffset = uint16_t;
-using RecordSize = uint16_t;
-using RecordType = uint16_t;
-using RecordLength = uint16_t;
-using KwSize = uint8_t;
-using PoundKwSize = uint16_t;
-using ECCOffset = uint16_t;
-using ECCLength = uint16_t;
-using LE2ByteData = uint16_t;
-
-} // namespace
-
 /** @class Impl
  *  @brief Implements parser for VPD
  *
@@ -165,7 +149,7 @@
     /** @brief This interface collects Offset of VTOC
      *  @returns VTOC Offset
      */
-    RecordOffset getVtocOffset() const;
+    openpower::vpd::constants::RecordOffset getVtocOffset() const;
 
     /** @brief VPD in binary format */
     Binary vpd;