1, PeiPcdLib use EFI_PEI_PCD_PPI defined in PI 1.2 to handle dynamicEx type PCD request.

2, DxePcdLib use EFI_PCD_PROTOCOL defined in PI 1.2 to handle dynamicEx type PCD request.
3, There is no change for dynamic type PCD.
4, Refine the INF's comments.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9473 6f19259b-4bc3-4df7-8a09-765794883524

MdePkg/Library/DxePcdLib/DxePcdLib.inf

@@ -1,9 +1,19 @@
 #/** @file
 # Instance of PCD Library using PCD Protocol.
 #
-# PCD Library that uses the PCD Protocol to access Dynamic and DynamicEx PCD entries.
+# There are two PCD PPIs as follows:
+#   1) PCD_PROTOCOL
+#      It is EDKII implementation which support Dynamic/DynamicEx Pcds.
+#   2) EFI_PCD_PROTOCOL
+#      It is defined by PI specification 1.2, Vol 3 which only support dynamicEx 
+#      type Pcd.
 #
-# Copyright (c) 2007 - 2008, Intel Corporation.
+# For dynamicEx type PCD, it is compatible between PCD_PROTOCOL and EFI_PCD_PROTOCOL.
+#
+# This library instance uses the PCD_PROTOCOL to handle dynamic PCD request and use
+# EFI_PCD_PROTOCOL to handle dynamicEx type PCD.
+#
+# Copyright (c) 2007 - 2009, Intel Corporation.
 #
 #  All rights reserved. This program and the accompanying materials
 #  are licensed and made available under the terms and conditions of the BSD License
@@ -44,7 +54,8 @@
 
 [Protocols]
   gPcdProtocolGuid                              ## CONSUMES
-
+  gEfiPcdProtocolGuid                           ## CONSUMES
+  
 [Depex]
-  gPcdProtocolGuid
+  gEfiPcdProtocolGuid