Switch back to the BSDL DTC (Device Tree Compiler).

The BSDL dtc has grown the needed features (overlays mostly) and is able to
compile all of our base DTS.
You can use WITH_GPL_DTC is you need the GPL one or DTC= in make.conf(5)
to specify an alternate location for the compiler to use.

Discussed with: emaste, imp

UPDATING

@@ -51,6 +51,10 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 12.x IS SLOW:
 
 ****************************** SPECIAL WARNING: ******************************
 
+20170620:
+	Switch back to the BSDL dtc (Device Tree Compiler), Set WITH_GPL_DTC
+	if you require the GPL compiler.
+
 20170618:
 	The internal ABI used for communication between the NFS kernel modules
 	was changed by r320085, so __FreeBSD_version was bumped to

share/mk/src.opts.mk

@@ -101,7 +101,6 @@ __DEFAULT_YES_OPTIONS = \
     GNU_DIFF \
     GNU_GREP \
     GPIO \
-    GPL_DTC \
     HAST \
     HTML \
     HYPERV \
@@ -181,6 +180,7 @@ __DEFAULT_NO_OPTIONS = \
     CLANG_EXTRAS \
     DTRACE_TESTS \
     GNU_GREP_COMPAT \
+    GPL_DTC \
     HESIOD \
     LIBSOFT \
     NAND \