update Fpd2Dsc.exe interface to sync users guide and add tool usage in ReadMe.txt. where Fpd2Dsc.exe source is r767 in BaseTools project.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@3940 6f19259b-4bc3-4df7-8a09-765794883524
1 file changed