Nand boot: Add nand boot support for MPC8569mds board

This patch add nand boot support for MPC8569mds board.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
diff --git a/Makefile b/Makefile
index 69b963f..c4ef585 100644
--- a/Makefile
+++ b/Makefile
@@ -2490,6 +2490,7 @@
 	@$(MKCONFIG) $(@:_config=) ppc mpc85xx mpc8568mds freescale
 
 MPC8569MDS_ATM_config \
+MPC8569MDS_NAND_config \
 MPC8569MDS_config:	unconfig
 	@$(MKCONFIG) -t $(@:_config=) MPC8569MDS ppc mpc85xx mpc8569mds freescale