docker/coreboot-sdk: Add device-tree-compiler

Add dtc to Dockerimage for Jenkins.

Change-Id: Ifa3608f0a83431e75fbd402385863cce06e249fb
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/25525
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

util/docker/coreboot-sdk/Dockerfile

@@ -25,6 +25,7 @@ RUN \
 		ccache \
 		cmake \
 		curl \
+		device-tree-compiler \
 		dh-autoreconf \
 		diffutils \
 		doxygen \