configs: Migrate CONFIG_NR_DRAM_BANKS

We have the following cases:
- CONFIG_NR_DRAM_BANKS was defined, migrate normally
- CONFIG_NR_DRAM_BANKS_MAX was defined and then used for
  CONFIG_NR_DRAM_BANKS after a check, just migrate it over now.
- CONFIG_NR_DRAM_BANKS was very oddly defined on p2771-0000-* (to 1024 +
  2), set this to 8.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/Itead_Ibox_A20_defconfig b/configs/Itead_Ibox_A20_defconfig
index dfef071..c5892ac 100644
--- a/configs/Itead_Ibox_A20_defconfig
+++ b/configs/Itead_Ibox_A20_defconfig
@@ -7,6 +7,7 @@
 CONFIG_SATAPWR="PB8"
 CONFIG_DEFAULT_DEVICE_TREE="sun7i-a20-itead-ibox"
 CONFIG_AHCI=y
+CONFIG_NR_DRAM_BANKS=1
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
 CONFIG_SPL_I2C_SUPPORT=y
 # CONFIG_CMD_FLASH is not set