ram: add ddr4 dual x8 configuration

the aspeed ddr sdram controller needs to know if the memory chip mounted on
the board is dual x8 die or not. Or it may get the wrong size of the
memory space.

Signed-off-by: Dylan Hung <dylan_hung@aspeedtech.com>
Reviewed-by: Ryan Chen <ryan_chen@aspeedtech.com>
diff --git a/drivers/ram/aspeed/Kconfig b/drivers/ram/aspeed/Kconfig
new file mode 100644
index 0000000..020c913
--- /dev/null
+++ b/drivers/ram/aspeed/Kconfig
@@ -0,0 +1,10 @@
+if RAM || SPL_RAM
+config ASPEED_DDR4_DUALX8
+	bool "Enable Dual X8 DDR4 die"
+	depends on DM && OF_CONTROL && ARCH_ASPEED
+	default n
+	help
+		Say Y if dual X8 DDR4 die is used on the board.  The aspeed ddr sdram
+		controller needs to know if the memory chip mounted on the board is dual
+		 x8 die or not.  Or it may get the wrong size of the memory space.
+endif