Roll back the change in Partition driver. currently we enhance the EHCI driver to...

Roll back the change in Partition driver. currently we enhance the EHCI driver to guarantee that the EHCI controller get attached to the EHCI controller before the UHCI driver attaches to the UHCI controller. This way can avoid the case happen that UHCI sees the disconnect and EHCI sees the connect event due to the control transfer in shared port. It may cause Partition.Start to be interrupted by Partition.Stop.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@8991 6f19259b-4bc3-4df7-8a09-765794883524