Android o preview 2
Update to dtc-1.4.4

Merge dtc to upstream 558cd81bdd432769b59bff01240c44f82cfb1a9d
and merge history

Bug: 37655045
Test: Build dtc, use output dtc to build dts, can output correct dtb.
Change-Id: Ibd9a82768e999bc46e6de349ca97ba6447e85455