2.Fix a bug in EBC, the periodic callback timer should be 1s
3.Add a dependency file for DriverSample in UI since it consume EFI_SIMPLE_TEXT_OUT protocol.
4.Fix a memory allocation defects in DriverSample.
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@2227 6f19259b-4bc3-4df7-8a09-765794883524