arm: mvebu: configs: armada8k: use 2 DRAM banks

Commit 2b4d964718c0 ("arm64: mvebu: a8k: autodetect RAM size") added an
ATF query to get the detected RAM size on Armada 8K platforms. To be
usable we must have 2 DRAM banks. Set Armada 8K configurations to 2
banks.

Cc: Konstantin Porotchkin <kostap@marvell.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/configs/mvebu_mcbin-88f8040_defconfig b/configs/mvebu_mcbin-88f8040_defconfig
index 9f72b76..44436bc 100644
--- a/configs/mvebu_mcbin-88f8040_defconfig
+++ b/configs/mvebu_mcbin-88f8040_defconfig
@@ -9,7 +9,7 @@
 CONFIG_DEBUG_UART=y
 CONFIG_AHCI=y
 CONFIG_DISTRO_DEFAULTS=y
-CONFIG_NR_DRAM_BANKS=1
+CONFIG_NR_DRAM_BANKS=2
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
 # CONFIG_DISPLAY_CPUINFO is not set