zero memory allocations. add support for virtual devices without driver binding. add #define protection for the header. git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@11431 6f19259b-4bc3-4df7-8a09-765794883524
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10887 6f19259b-4bc3-4df7-8a09-765794883524
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10874 6f19259b-4bc3-4df7-8a09-765794883524