Convert CONFIG_DP_DDR_DIMM_SLOTS_PER_CTLR to Kconfig

This converts the following to Kconfig:
   CONFIG_DP_DDR_DIMM_SLOTS_PER_CTLR

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
index 5a809b4..3ea023d 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
+++ b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
@@ -511,6 +511,11 @@
 	depends on SYS_FSL_HAS_DP_DDR
 	default 2 if ARCH_LS2080A
 
+config DP_DDR_DIMM_SLOTS_PER_CTLR
+	int
+	depends on SYS_FSL_HAS_DP_DDR
+	default 1 if ARCH_LS2080A
+
 config DP_DDR_NUM_CTRLS
 	int
 	depends on SYS_FSL_HAS_DP_DDR