respect pkg-config env settings

Rather than use the host's pkg-config, we want to use the target's.
This way we query the right .pc files.

BUG=None
TEST=`emerge vboot_reference` still works
TEST=`emerge-arm-generic vboot_reference` still works

Change-Id: I083a987ee6c23716f8d79eb14e7c38c12e18b8f8
Reviewed-on: https://gerrit.chromium.org/gerrit/24727
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
2 files changed