ppc/85xx: simplify the top makefile for 36-bit config for mpc8536ds

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/Makefile b/Makefile
index 0b61d05..99837a3 100644
--- a/Makefile
+++ b/Makefile
@@ -2448,9 +2448,7 @@
 
 MPC8536DS_36BIT_config \
 MPC8536DS_config:       unconfig
-	@mkdir -p $(obj)include
-	@echo "#define CONFIG_$(@:_config=) 1"	>$(obj)include/config.h
-	@$(MKCONFIG) -a MPC8536DS ppc mpc85xx mpc8536ds freescale
+	@$(MKCONFIG) -t $(@:_config=) MPC8536DS ppc mpc85xx mpc8536ds freescale
 
 MPC8540ADS_config:	unconfig
 	@$(MKCONFIG) $(@:_config=) ppc mpc85xx mpc8540ads freescale
diff --git a/include/configs/MPC8536DS.h b/include/configs/MPC8536DS.h
index 4746e2e..faca805 100644
--- a/include/configs/MPC8536DS.h
+++ b/include/configs/MPC8536DS.h
@@ -27,7 +27,7 @@
 #ifndef __CONFIG_H
 #define __CONFIG_H
 
-#ifdef CONFIG_MPC8536DS_36BIT
+#ifdef CONFIG_MK_36BIT
 #define CONFIG_PHYS_64BIT	1
 #endif