Add dd as a bootstrap tool, for status= support

In r295757 I added status=none to buildworld's use of dd, but FreeBSD
versions before April 2014 lack support.

Makefile.inc1

@@ -1471,6 +1471,11 @@ ${_bt}-usr.sbin/nmtree: ${_bt}-lib/libnetbsd
 _cat=		bin/cat
 .endif
 
+# r264059 support for status=
+.if ${BOOTSTRAPPING} < 1100017
+_dd=		bin/dd
+.endif
+
 # r277259 crunchide: Correct 64-bit section header offset
 # r281674 crunchide: always include both 32- and 64-bit ELF support
 # r285986 crunchen: use STRIPBIN rather than STRIP
@@ -1546,6 +1551,7 @@ bootstrap-tools: .PHONY
     ${_dtc} \
     ${_awk} \
     ${_cat} \
+    ${_dd} \
     usr.bin/lorder \
     ${_libopenbsd} \
     ${_makewhatis} \