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/mx6qarm2_lpddr2_defconfig b/configs/mx6qarm2_lpddr2_defconfig
index d707867..5002091 100644
--- a/configs/mx6qarm2_lpddr2_defconfig
+++ b/configs/mx6qarm2_lpddr2_defconfig
@@ -3,6 +3,7 @@
 CONFIG_SYS_TEXT_BASE=0x17800000
 CONFIG_TARGET_MX6QARM2=y
 # CONFIG_CMD_BMODE is not set
+CONFIG_NR_DRAM_BANKS=1
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=board/freescale/mx6qarm2/imximage.cfg,MX6Q,MX6DQ_LPDDR2,DDR_MB=512"
 CONFIG_BOOTDELAY=3
 CONFIG_SUPPORT_RAW_INITRD=y