dtc: upgraded to 1.5.0

Needed for new QEMU.

NB: added tc-export for PKG_CONFIG to account for
https://crrev.com/c/1715466. Sent upstream here:

https://github.com/gentoo/gentoo/pull/16611

BUG=chromium:1099508
TEST=build

Change-Id: Ic6a7664d04ae7d93f316d03e2702811f6016101b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/2278488
Tested-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Brian Norris <briannorris@chromium.org>
9 files changed