ARM: FDT: add DTS[I] files for the first couple of targets.

Both for the rPI and the Verdex target we now have FDTs. The verdex
DTS is homebrew, the pxa DTSIs come from Linux and should be kept
in sync.

The rPI DTS and Broadcom DTSI come from FreeBSD HEAD, and should
ofcourse also be kept in sync.

One global new Jam rule has been introduced for handling DTS
compilation, aptly named CompileDTS....

More coming!

build/jam/MainBuildRules

@@ -181,6 +181,16 @@ actions AssembleNasm
 	fi
 }
 
+rule CompileDTS
+{
+	Depends $(<) : $(>) ;
+}
+
+actions CompileDTS
+{
+	dtc -O dtb -o $(1) $(2);
+}
+
 rule Ld
 {
 	# Ld <name> : <objs> : <linkerscript> : <flags> ;