Flattened the platform directory structure

Flattened the platform directory structure

BZ: 22780

Moved the contents of both mrst and mfld directories to a single folder (intel-mid/).

Change-Id: I78d8915b4513f0032e5221eaa2bc79edfbf4512b
Signed-off-by: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
Reviewed-on: http://android.intel.com:8080/34378
Reviewed-by: Yang, Fei <fei.yang@intel.com>
Tested-by: Yang, Fei <fei.yang@intel.com>
Reviewed-by: Wood, Brian J <brian.j.wood@intel.com>
Tested-by: Wood, Brian J <brian.j.wood@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>