Add Imagination Technologies to AUTHORS file

BUG=b:117489304
TEST=None

Change-Id: I551877e5b4ea970bf52a68e28c9418a812bc5f3a
Reviewed-on: https://chromium-review.googlesource.com/c/1320011Reviewed-by: Miguel Casas <mcasas@chromium.org>
Commit-Queue: Bernie Thompson <bhthompson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605782}

AUTHORS

@@ -998,6 +998,7 @@ Hewlett-Packard Development Company, L.P. <*@hp.com>
 IBM Inc. <*@*.ibm.com>
 IBM Inc. <*@ibm.com>
 Igalia S.L. <*@igalia.com>
+Imagination Technologies Limited <*@imagination.corp-partner.google.com>
 Impossible Dreams Network <*@impossibledreams.net>
 LG Electronics, Inc. <*@lge.com>
 Loongson Technology Corporation Limited. <*@loongson.cn>