Patch merged into filo/master: ba947af makefile: create directories on demand

the following patch was just integrated into master:
commit ba947af8efc8d7d5b403150ed16a8c61cdd9750d
Author: Mathias Krause 
Date:   Tue Mar 6 09:31:38 2012 +0100

makefile: create directories on demand

Use makefile dependencies to created needed directories instead of
    trying to recreate them on each make invocation.

Change-Id: Ia06b1042f2a2c4905f5c8277a48ec4b8188f3079
    Signed-off-by: Mathias Krause

Build-Tested: build bot (Jenkins) at Tue Mar  6 16:47:07 2012, giving +1
Reviewed-By: Stefan Reinauer  at Tue Mar  6 21:53:30 2012, giving +2
See http://review.coreboot.org/742 for details.

-gerrit