Using the update-dtc-source.sh script from Linux v4.14-rc1 import the
portions of dtc that we require. We bring in update-dtc-source.sh and
scripts/dtc/Makefile from Linux v4.14-rc1. Rework DTC_FLAGS handling to
not require a test.
Signed-off-by: Tom Rini <trini@konsulko.com>
Tom Rini