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/stm32h743-disco_defconfig b/configs/stm32h743-disco_defconfig
index e98d18c..1cf8ee8 100644
--- a/configs/stm32h743-disco_defconfig
+++ b/configs/stm32h743-disco_defconfig
@@ -6,6 +6,7 @@
 CONFIG_TARGET_STM32H743_DISCO=y
 CONFIG_DEFAULT_DEVICE_TREE="stm32h743i-disco"
 CONFIG_DISTRO_DEFAULTS=y
+CONFIG_NR_DRAM_BANKS=1
 CONFIG_BOOTDELAY=3
 # CONFIG_USE_BOOTCOMMAND is not set
 CONFIG_DEFAULT_FDT_FILE="stm32h743i-disco"