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/imx6ul_isiot_emmc_defconfig b/configs/imx6ul_isiot_emmc_defconfig
index 684f231..ad5d902 100644
--- a/configs/imx6ul_isiot_emmc_defconfig
+++ b/configs/imx6ul_isiot_emmc_defconfig
@@ -11,6 +11,7 @@
 CONFIG_SPL_LIBDISK_SUPPORT=y
 # CONFIG_CMD_BMODE is not set
 CONFIG_DEFAULT_DEVICE_TREE="imx6ul-isiot-emmc"
+CONFIG_NR_DRAM_BANKS=1
 CONFIG_FIT=y
 CONFIG_FIT_SIGNATURE=y
 CONFIG_FIT_VERBOSE=y