OWNERS: Add firmware team to OWNERS of related directories

Add firmware team members who make frequent changes to /FIRMWARE_OWNERS.

Co-own the directories, with many other teams:
 * server/cros  # for library likes vboot_constants.py
 * server/site_tests  # for adding new tests

Exclusive co-own (set noparent) the directories, with EngProd team:
 * client/cros/faft
 * server/cros/faft

Open to everyone:
 * server/cros/faft/config

BUG=chromium:968130
TEST=None

Change-Id: If710efe5fa8a7d55a5116dce94f54702ca2c3b0b
Reviewed-on: https://chromium-review.googlesource.com/1713889
Tested-by: Wai-Hong Tam <waihong@google.com>
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: C Shapiro <shapiroc@chromium.org>
diff --git a/FIRMWARE_OWNERS b/FIRMWARE_OWNERS
new file mode 100644
index 0000000..35468ca
--- /dev/null
+++ b/FIRMWARE_OWNERS
@@ -0,0 +1,11 @@
+# ChromeOS firmware team
+
+aaboagye@chromium.org
+alevkoy@chromium.org
+dlaurie@google.com
+jwerner@chromium.org
+mruthven@chromium.org
+namyoon@chromium.org
+shchen@chromium.org
+vbendeb@chromium.org
+waihong@google.com