ARM: atmel: sama5d4: build related file when enable SPL

Signed-off-by: Bo Shen <voice.shen@atmel.com>

arch/arm/cpu/at91-common/Makefile

@@ -13,5 +13,6 @@ ifneq ($(CONFIG_SPL_BUILD),)
 obj-$(CONFIG_AT91SAM9G20) += sdram.o spl_at91.o
 obj-$(CONFIG_AT91SAM9M10G45) += mpddrc.o spl_at91.o
 obj-$(CONFIG_SAMA5D3) += mpddrc.o spl_atmel.o
+obj-$(CONFIG_SAMA5D4) += mpddrc.o spl_atmel.o
 obj-y += spl.o
 endif