vboot_reference: Install 2id.h and vb21_struct.h header files.

Hammerd requires these header files of vboot_reference to
be published.

BUG=b:36139110
TEST=emerge-poppy vboot_reference and check these headers are installed.

Change-Id: Ic0f875f353ec320909874f0572651f10c29cff50
Reviewed-on: https://chromium-review.googlesource.com/513763
Commit-Ready: Chih-Yu Huang <akahuang@chromium.org>
Tested-by: Chih-Yu Huang <akahuang@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed