arm: socfpga: stratix10: add CONFIG_SPL_TARGET

Stratix10 combines the u-boot-spl image into the fpga configuration
bitstream so that the SDM can load the processors memory.  This
process requires a hex format of the u-boot-spl image.
CONFIG_SPL_TARGET is set to "spl/u-boot-spl.hex"

Signed-off-by: Dalon Westergreen <dwesterg@gmail.com>
diff --git a/include/configs/socfpga_stratix10_socdk.h b/include/configs/socfpga_stratix10_socdk.h
index b58f478..91315a0 100644
--- a/include/configs/socfpga_stratix10_socdk.h
+++ b/include/configs/socfpga_stratix10_socdk.h
@@ -202,6 +202,7 @@
  * 0x8000_0000 ...... End of SDRAM_1 (assume 2GB)
  *
  */
+#define CONFIG_SPL_TARGET		"spl/u-boot-spl.hex"
 #define CONFIG_SPL_TEXT_BASE		CONFIG_SYS_INIT_RAM_ADDR
 #define CONFIG_SPL_MAX_SIZE		CONFIG_SYS_INIT_RAM_SIZE
 #define CONFIG_SPL_STACK		CONFIG_SYS_INIT_SP_ADDR