Convert CONFIG_CHIP_SELECTS_PER_CTRL to Kconfig

This converts the following to Kconfig:
   CONFIG_CHIP_SELECTS_PER_CTRL

Cc: Alison Wang <alison.wang@nxp.com>
Cc: Pramod Kumar <pramod.kumar_1@nxp.com>
Cc: Priyanka Jain <priyanka.jain@nxp.com>
Cc: Rajesh Bhagat <rajesh.bhagat@nxp.com>
Cc: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/MPC8548CDS_legacy_defconfig b/configs/MPC8548CDS_legacy_defconfig
index d6addc7..ae262bf 100644
--- a/configs/MPC8548CDS_legacy_defconfig
+++ b/configs/MPC8548CDS_legacy_defconfig
@@ -32,6 +32,7 @@
 CONFIG_USE_BOOTFILE=y
 CONFIG_BOOTFILE="8548cds/uImage.uboot"
 CONFIG_DM=y
+CONFIG_CHIP_SELECTS_PER_CTRL=2
 CONFIG_DDR_ECC=y
 CONFIG_ECC_INIT_VIA_DDRCONTROLLER=y
 CONFIG_SYS_BR0_PRELIM_BOOL=y