Add 'tags' target to Makefile

Handy for quick code searches.

BUG=none
BRANCH=ToT
TEST=manual

  make tags

Change-Id: Icc21769a168d1760f4f21802e1183a519cfeb019
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/214620
Reviewed-by: Randall Spangler <rspangler@chromium.org>
1 file changed