MdePkg/IndustryStandard: Update Atapi.h to comply with latest ATA8-ACS spec (d2015r7)

Signed-off-by: Feng Tian <feng.tian@intel.com>
Reviewed-by: Elvin Li <elvin.li@intel.com>


git-svn-id: svn://svn.code.sf.net/p/edk2/code/trunk/edk2/MdePkg@14554 6f19259b-4bc3-4df7-8a09-765794883524