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/mx6slevk_defconfig b/configs/mx6slevk_defconfig
index 4b72e08..2cf4004 100644
--- a/configs/mx6slevk_defconfig
+++ b/configs/mx6slevk_defconfig
@@ -4,6 +4,7 @@
 CONFIG_TARGET_MX6SLEVK=y
 # CONFIG_CMD_BMODE is not set
 CONFIG_DEFAULT_DEVICE_TREE="imx6sl-evk"
+CONFIG_NR_DRAM_BANKS=1
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=board/freescale/mx6slevk/imximage.cfg"
 CONFIG_SUPPORT_RAW_INITRD=y
 CONFIG_BOARD_EARLY_INIT_F=y