system_api: Drop unused *EnrollmentState

BUG=chromium:800748
TEST=both Chrome and cryptohomed still compile

Change-Id: I365ed096571e515fa0767ec2936b2c4081289f43
Reviewed-on: https://chromium-review.googlesource.com/859766
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Thiemo Nagel <tnagel@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
1 file changed