[u2f] Add jdoerrie@ to OWNERS

Bug: NONE
Change-Id: I5e79a366942948f8361f25db0d2cae68a412c016
Reviewed-on: https://chromium-review.googlesource.com/809107
Commit-Queue: Jan Wilken Dörrie <jdoerrie@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522054}

device/u2f/OWNERS

+jdoerrie@chromium.org
+
+# COMPONENT: Blink>WebAuthentication