Sync patches r14285, r14302 and r14303 from main trunk.
1. Allocate ACPImemoryNVS type memory to save mailbox and debug port handle buffer since original allocated pool memory may be marked as free by DXE Core.
2. Add CPU arch type in Mailbox, debug agent will not access HOB if CPU arch changed.
3. Updated DxeDebugAgentLib instance to copy DebugPortHandler buffer into allocated ACPIMemoryNVS besides the mailbox.
4. Remove deprecated SendingPacket from mailbox.


git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/branches/UDK2010.SR1@14304 6f19259b-4bc3-4df7-8a09-765794883524