Add third_party/libva_protected_content

This is an additional header file for using libva in protected content
mode that was supplied by Intel. This will not be merged into libva
directly as it pertains to closed source functionality in the iHD
driver. libva is able to pass through these details without knowing
about them.

BUG=b:153111783
TEST=None

Change-Id: I10759537cd653e9a541b30931c6474c014dbb256
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2523100Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Jeffrey Kardatzke <jkardatzke@google.com>
Cr-Commit-Position: refs/heads/master@{#825379}

third_party/libva_protected_content/LICENSE

+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the
+    "Software"), to deal in the Software without restriction, including
+    without limitation the rights to use, copy, modify, merge, publish,
+    distribute, sub license, and/or sell copies of the Software, and to
+    permit persons to whom the Software is furnished to do so, subject to
+    the following conditions:
+
+    The above copyright notice and this permission notice (including the
+    next paragraph) shall be included in all copies or substantial portions
+    of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+    IN NO EVENT SHALL PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR
+    ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+    TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

third_party/libva_protected_content/OWNERS

+jkardatzke@chromium.org
+marcheu@chromium.org

third_party/libva_protected_content/README.chromium

+Name: Protected Content Interface for libva
+Short Name: libva_protected_content
+Version: 2.9.0
+Date: 2020-11-02
+License: MIT
+License File: LICENSE
+Security Critical: no
+
+Description:
+This contains a header file supplied by Intel that is used for protected content
+functionality with libva. All the functional pieces are contained within libva
+and the corresponding driver implementation beneath libva. The entrypoints,
+attributes and buffers defined here are passed through by libva to the driver
+implementation which utilizes these as part of a closed source implementation
+for Chrome OS for playing back protected content.
\ No newline at end of file