rockchip: rename board.c to rk3288-board.c

Signed-off-by: Jacob Chen <jacob2.chen@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/mach-rockchip/Makefile b/arch/arm/mach-rockchip/Makefile
index 157d42f..e31b8de 100644
--- a/arch/arm/mach-rockchip/Makefile
+++ b/arch/arm/mach-rockchip/Makefile
@@ -9,7 +9,7 @@
 obj-$(CONFIG_ROCKCHIP_RK3288) += rk3288-board-spl.o
 obj-$(CONFIG_ROCKCHIP_SPL_BACK_TO_BROM) += save_boot_param.o
 else
-obj-$(CONFIG_ROCKCHIP_RK3288) += board.o
+obj-$(CONFIG_ROCKCHIP_RK3288) += rk3288-board.o
 endif
 ifndef CONFIG_ARM64
 obj-y += rk_timer.o