EmbeddedPkg: implement EDK2 IoMmu protocol wrapping DmaLib

Implement a version of the EDK2 IoMmu protocol that is a simple wrapper
around DmaLib. This is intended to be used to wrap NonCoherentDmaLib so
that the generic PCI infrastructure can be used to implement support for
non cache-coherent DMA.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Tested-by: Pete Batard <pete@akeo.ie>

EmbeddedPkg/Drivers/NonCoherentIoMmuDxe/NonCoherentIoMmuDxe.inf

@@ -0,0 +1,43 @@
+#/** @file
+#
+#  Copyright (c) 2019, Linaro, Ltd. 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.
+#
+#**/
+
+[Defines]
+  INF_VERSION                    = 1.27
+  BASE_NAME                      = NonCoherentIoMmuDxe
+  FILE_GUID                      = 7ed510aa-9cdc-49d2-a306-6e11e359f9b3
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  ENTRY_POINT                    = NonCoherentIoMmuDxeEntryPoint
+
+[Sources]
+  NonCoherentIoMmuDxe.c
+
+[Packages]
+  EmbeddedPkg/EmbeddedPkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
+  DmaLib
+  UefiBootServicesTableLib
+  UefiDriverEntryPoint
+
+[Protocols]
+  gEdkiiIoMmuProtocolGuid                     ## PRODUCES
+
+[Depex]
+  TRUE