driver/ddr/altera: Add DDR driver for Altera's SDRAM controller

This patch enables the SDRAM controller that is used on Altera's SoCFPGA
family. This patch configures the SDRAM controller based on a configuration
file that is generated from the Quartus tool, sdram_config.h.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
diff --git a/scripts/Makefile.spl b/scripts/Makefile.spl
index b1047b5..4879d0a 100644
--- a/scripts/Makefile.spl
+++ b/scripts/Makefile.spl
@@ -62,6 +62,7 @@
 libs-$(CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT) += drivers/ddr/fsl/
 libs-$(CONFIG_SYS_MVEBU_DDR_A38X) += drivers/ddr/marvell/a38x/
 libs-$(CONFIG_SYS_MVEBU_DDR_AXP) += drivers/ddr/marvell/axp/
+libs-$(CONFIG_ALTERA_SDRAM) += drivers/ddr/altera/
 libs-$(CONFIG_SPL_SERIAL_SUPPORT) += drivers/serial/
 libs-$(CONFIG_SPL_SPI_FLASH_SUPPORT) += drivers/mtd/spi/
 libs-$(CONFIG_SPL_SPI_SUPPORT) += drivers/spi/