board: silinux: Enable recovery SPL for EK874 board

Enable building SPL for EK874 board which is based on R8A774C0 SoC.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
diff --git a/board/silinux/ek874/Makefile b/board/silinux/ek874/Makefile
index 32a3a00..4c8f092 100644
--- a/board/silinux/ek874/Makefile
+++ b/board/silinux/ek874/Makefile
@@ -6,4 +6,8 @@
 # SPDX-License-Identifier: GPL-2.0+
 #
 
+ifdef CONFIG_SPL_BUILD
+obj-y	:= ../../renesas/rcar-common/gen3-spl.o
+else
 obj-y	:= ek874.o ../../renesas/rcar-common/common.o
+endif