[Blackfin] arch: boards and machines defconfig updates

Signed-off-by: Bryan Wu <cooloney@kernel.org>

diff --git a/arch/blackfin/configs/CM-BF537E_defconfig b/arch/blackfin/configs/CM-BF537E_defconfig
index 36a7244..9f66d2d 100644
--- a/arch/blackfin/configs/CM-BF537E_defconfig
+++ b/arch/blackfin/configs/CM-BF537E_defconfig
@@ -218,7 +218,7 @@
 #
 # Memory Setup
 #
-CONFIG_MEM_SIZE=32
+CONFIG_MAX_MEM_SIZE=32
 CONFIG_MEM_ADD_WIDTH=9
 CONFIG_BOOT_LOAD=0x1000
 CONFIG_BFIN_SCRATCH_REG_RETN=y