MdeModulePkg: Add RamDiskDxe driver implementation

The RamDiskDxe driver will:
1. Produce the EFI RAM Disk Protocol
2. Install RAM disk device path and block I/O related protocols on the
   RAM disk device handle.
3. Install RAM disk configuration form to HII database

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Samer El-Haj-Mahmoud <elhaj@hpe.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>

MdeModulePkg/Include/Guid/RamDiskHii.h

@@ -0,0 +1,25 @@
+/** @file
+  GUIDs used as HII FormSet and HII Package list GUID in RamDiskDxe driver.
+
+  Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
+  This program and the accompanying materials
+  are licensed and made available under the terms and conditions of the BSD License
+  which accompanies this distribution.  The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#ifndef __RAM_DISK_HII_GUID_H__
+#define __RAM_DISK_HII_GUID_H__
+
+#define RAM_DISK_FORM_SET_GUID \
+  { \
+    0x2a46715f, 0x3581, 0x4a55, {0x8e, 0x73, 0x2b, 0x76, 0x9a, 0xaa, 0x30, 0xc5} \
+  }
+
+extern EFI_GUID gRamDiskFormSetGuid;
+
+#endif