dtc: mkimage: Add the possibility to specify DTC

FreeBSD recently switch to it's BSDL dtc. While it support most of the
features of the GPL one it still lacks the incbin directive.
Add the possibility to specify which dtc we want to use for compiling dts
and generating fit image.

Signed-off-by: Emmanuel Vadot <manu@bidouilliste.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/Makefile b/Makefile
index 4525964..a5f5688 100644
--- a/Makefile
+++ b/Makefile
@@ -349,7 +349,7 @@
 AWK		= awk
 PERL		= perl
 PYTHON		?= python
-DTC		= dtc
+DTC		?= dtc
 CHECK		= sparse
 
 CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
diff --git a/tools/Makefile b/tools/Makefile
index cb1683e..62a7921 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -175,6 +175,8 @@
 endif
 endif
 
+HOSTCFLAGS_fit_image.o += -DMKIMAGE_DTC=\"$(DTC)\"
+
 HOSTLOADLIBES_dumpimage := $(HOSTLOADLIBES_mkimage)
 HOSTLOADLIBES_fit_info := $(HOSTLOADLIBES_mkimage)
 HOSTLOADLIBES_fit_check_sign := $(HOSTLOADLIBES_mkimage)
diff --git a/tools/mkimage.h b/tools/mkimage.h
index 3f369b7..baee866 100644
--- a/tools/mkimage.h
+++ b/tools/mkimage.h
@@ -44,6 +44,5 @@
 #define MKIMAGE_MAX_TMPFILE_LEN		256
 #define MKIMAGE_DEFAULT_DTC_OPTIONS	"-I dts -O dtb -p 500"
 #define MKIMAGE_MAX_DTC_CMDLINE_LEN	512
-#define MKIMAGE_DTC			"dtc"   /* assume dtc is in $PATH */
 
 #endif /* _MKIIMAGE_H_ */