vboot_reference: remove dependency on trousers

This is done to break a circular DEPENDency as we want to
send UMA stats from tcsd.  Without this, metrics depends on
vboot_reference which depends on trousers which depends on
metrics.  Technically the vboot_reference dependency on trousers
is header-file only, but we can't cope with that.

BUG=chromium:481552
TEST=compiled with emerge-<something> vboot_reference
BRANCH=none

Change-Id: Iea5c0c39bb70977c9d375e63ea607687debe9f9f
Reviewed-on: https://chromium-review.googlesource.com/267744
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Commit-Queue: Luigi Semenzato <semenzato@chromium.org>
Tested-by: Luigi Semenzato <semenzato@chromium.org>
3 files changed