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/bananapi_m64_defconfig b/configs/bananapi_m64_defconfig
index 40c1c18..ebc29e3 100644
--- a/configs/bananapi_m64_defconfig
+++ b/configs/bananapi_m64_defconfig
@@ -6,6 +6,7 @@
 CONFIG_MMC0_CD_PIN="PH13"
 CONFIG_MMC_SUNXI_SLOT_EXTRA=2
 CONFIG_DEFAULT_DEVICE_TREE="sun50i-a64-bananapi-m64"
+CONFIG_NR_DRAM_BANKS=1
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
 # CONFIG_CMD_FLASH is not set
 # CONFIG_SPL_DOS_PARTITION is not set