feat(lib): modify Hob creation code imported from edk2

According to Platform Initialization (PI) Specification [1] and
Discussion on edk2 mailing list [2],
StandaloneMm shouldn't create Hob but it should be passed from TF-A.
IOW, TF-A should pass boot information via PHIT Hob to initialize
StandaloneMm properly.

This patch modifies Hob creation code from edk2 codebase
so that TF-A could create Hob information properly to boot StandaloneMm

Link: https://uefi.org/sites/default/files/resources/PI_Spec_1_6.pdf [1]
Link: https://edk2.groups.io/g/devel/topic/103675962#114283 [2]
Signed-off-by: Levi Yun <yeoreum.yun@arm.com>
Change-Id: I5e427b620d8006b118b266370bd08d4b0ff56a83
diff --git a/docs/license.rst b/docs/license.rst
index 9e0298b..22d0e06 100644
--- a/docs/license.rst
+++ b/docs/license.rst
@@ -110,6 +110,12 @@
    -  ``tools/cot_dt2c/cot_dt2c/pydevicetree/source/parser.py``
    -  ``tools/cot_dt2c/cot_dt2c/pydevicetree/__init__.py``
 
+-  Some source files originating from the `edk2`_ project.
+   These files are licensed under the BSD-2-Clause. Any contributions to this
+   code must also be made under the terms of BSD-2-Clause.
+   These files are:
+
+   -  ``lib/hob/hob.c``
 
 .. _FreeBSD: http://www.freebsd.org
 .. _Linux MIT license: https://raw.githubusercontent.com/torvalds/linux/master/LICENSES/preferred/MIT
@@ -117,3 +123,4 @@
 .. _Open Profile for DICE: https://pigweed.googlesource.com/open-dice/
 .. _Apache License 2.0: https://www.apache.org/licenses/LICENSE-2.0.txt
 .. _pydevicetree: https://pypi.org/project/pydevicetree/
+.. _edk2: https://github.com/tianocore/edk2