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/bcm7445_defconfig b/configs/bcm7445_defconfig
index 8b42478..59c745f 100644
--- a/configs/bcm7445_defconfig
+++ b/configs/bcm7445_defconfig
@@ -2,6 +2,7 @@
 CONFIG_ARCH_BCMSTB=y
 CONFIG_SYS_TEXT_BASE=0x80100000
 CONFIG_TARGET_BCM7445=y
+CONFIG_NR_DRAM_BANKS=3
 CONFIG_FIT=y
 CONFIG_FIT_SIGNATURE=y
 CONFIG_BOOTDELAY=1