Update dtc to 1.6.0

Upstream commit 9d7888cbf19c.

Bug: 160825200
Change-Id: I1f8c79f09190af4025b186166a25b745710f2871
diff --git a/Android.bp b/Android.bp
index d52d98c..712bc4d 100644
--- a/Android.bp
+++ b/Android.bp
@@ -7,6 +7,7 @@
         "-Wno-sign-compare",
         "-Wno-missing-field-initializers",
         "-Wno-unused-parameter",
+        "-DNO_YAML"
     ],
 
     static_libs: ["libfdt"],