powerpc: T4240QDS: Remove macro CONFIG_T4240QDS

Use CONFIG_TARGET_T4240QDS instead.

Signed-off-by: York Sun <york.sun@nxp.com>
diff --git a/board/freescale/t4qds/Makefile b/board/freescale/t4qds/Makefile
index 6c51c74..1eacbcc 100644
--- a/board/freescale/t4qds/Makefile
+++ b/board/freescale/t4qds/Makefile
@@ -8,7 +8,7 @@
 obj-y	+= spl.o
 else
 obj-$(CONFIG_TARGET_T4160QDS)	+= t4240qds.o eth.o
-obj-$(CONFIG_T4240QDS)	+= t4240qds.o eth.o
+obj-$(CONFIG_TARGET_T4240QDS)	+= t4240qds.o eth.o
 obj-$(CONFIG_PCI)	+= pci.o
 endif