mx31: move freescale's mx31 boards to vendor board dir

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/Makefile b/Makefile
index 6624370..0defeca 100644
--- a/Makefile
+++ b/Makefile
@@ -2681,7 +2681,7 @@
 	@$(MKCONFIG) $(@:_config=) arm arm1136 imx31_phycore NULL mx31
 
 mx31ads_config		: unconfig
-	@$(MKCONFIG) $(@:_config=) arm arm1136 mx31ads NULL mx31
+	@$(MKCONFIG) $(@:_config=) arm arm1136 mx31ads freescale mx31
 
 omap2420h4_config	: unconfig
 	@$(MKCONFIG) $(@:_config=) arm arm1136 omap2420h4 NULL omap24xx