MdeModulePkg: Add PrePiHob.h

RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3937

BZ3937_EFI_RESOURCE_MEMORY_UNACCEPTED is defined for unaccepted memory.
But this defitinion has not been officially in the PI spec. Base
on the code-first we define BZ3937_EFI_RESOURCE_MEMORY_UNACCEPTED at
MdeModulePkg/Include/Pi/PrePiHob.h.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
Signed-off-by: Min Xu <min.m.xu@intel.com>

MdeModulePkg/Include/Pi/PrePiHob.h

@@ -0,0 +1,20 @@
+/** @file
+  HOB related definitions which has not been officially published in PI.
+
+Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef MDE_MODULEPKG_PRE_PI_HOB_H_
+#define MDE_MODULEPKG_PRE_PI_HOB_H_
+
+//
+// BZ3937_EFI_RESOURCE_MEMORY_UNACCEPTED is defined for unaccepted memory.
+// But this defitinion has not been officially in the PI spec. Base
+// on the code-first we define BZ3937_EFI_RESOURCE_MEMORY_UNACCEPTED at
+// MdeModulePkg/Include/Pi/PrePiHob.h.
+//
+#define BZ3937_EFI_RESOURCE_MEMORY_UNACCEPTED  0x00000007
+
+#endif