avr: use new code in latest nodes.

avr/devices/n21/0BUILD

@@ -2,44 +2,9 @@
 
 <gwbuild>
 
-  <target type="AvrHexFile" name="n21_firmware" >
-
-    <includes type="avrasm" >
-      -I $(builddir)
-      -I $(srcdir)
-      -I $(topsrcdir)/avr
-      -I $(topbuilddir)/avr
-    </includes>
-
-
-    <sources type="avrasm" >
-      main.asm
-    </sources>
-
-
-  </target>
-
-
-
-  <target type="AvrHexFile" name="n21_boot" >
-
-    <includes type="avrasm" >
-      -I $(builddir)
-      -I $(srcdir)
-      -I $(topsrcdir)/avr
-      -I $(topbuilddir)/avr
-    </includes>
-
-
-    <sources type="avrasm" >
-      boot.asm
-    </sources>
-
-
-  </target>
-
-
   <subdirs>
+    boot
+    main
   </subdirs>
 
   <extradist>