configs: Add DDR Kconfig support for Arria 10

This patch enables DDR Kconfig support for Arria 10.

Signed-off-by: Tien Fong Chee <tien.fong.chee@intel.com>
Reviewed-by: Dinh Nguyen <dinguyen@kernel.org>
diff --git a/arch/arm/mach-socfpga/Kconfig b/arch/arm/mach-socfpga/Kconfig
index 824c9fc..b8fc81b 100644
--- a/arch/arm/mach-socfpga/Kconfig
+++ b/arch/arm/mach-socfpga/Kconfig
@@ -10,6 +10,7 @@
 config TARGET_SOCFPGA_ARRIA10
 	bool
 	select SPL_BOARD_INIT if SPL
+	select ALTERA_SDRAM
 
 config TARGET_SOCFPGA_CYCLONE5
 	bool