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/ethernut5_defconfig b/configs/ethernut5_defconfig
index fd5a6f6..581b78b 100644
--- a/configs/ethernut5_defconfig
+++ b/configs/ethernut5_defconfig
@@ -4,6 +4,7 @@
 CONFIG_TARGET_ETHERNUT5=y
 CONFIG_SYS_MALLOC_F_LEN=0x2000
 CONFIG_DEFAULT_DEVICE_TREE="ethernut5"
+CONFIG_NR_DRAM_BANKS=1
 CONFIG_SYS_EXTRA_OPTIONS="AT91SAM9XE"
 CONFIG_BOOTDELAY=3
 CONFIG_USE_BOOTARGS=y