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/spear600_usbtty_nand_defconfig b/configs/spear600_usbtty_nand_defconfig
index 5b9c833..fd94a9a 100644
--- a/configs/spear600_usbtty_nand_defconfig
+++ b/configs/spear600_usbtty_nand_defconfig
@@ -2,6 +2,7 @@
 CONFIG_TARGET_SPEAR600=y
 CONFIG_SYS_TEXT_BASE=0x00700000
 CONFIG_IDENT_STRING="-SPEAr"
+CONFIG_NR_DRAM_BANKS=1
 CONFIG_SYS_EXTRA_OPTIONS="SPEAR600,USBTTY"
 CONFIG_BOOTDELAY=-1
 CONFIG_USE_BOOTARGS=y