Add afakhry@ to ash/accelerator/OWNERS

BUG=None

Change-Id: Ib8982c19f02e36181b0936d1ed63cffdbb5ad108
Reviewed-on: https://chromium-review.googlesource.com/695716Reviewed-by: Dan Erat <derat@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#505880}

ash/accelerators/OWNERS

+afakhry@chromium.org