rockchip: add u-boot-rockchip-spi.bin image for booting from SPI-NOR flash

This new image is similar to u-boot-rockchip.bin except that it's
destined to be flashed on SPI-NOR flashes.

Cc: Quentin Schulz <foss+uboot@0leil.net>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/Makefile b/Makefile
index 736c4ad..e70e92c 100644
--- a/Makefile
+++ b/Makefile
@@ -2197,7 +2197,8 @@
 	       idbloader.img flash.bin flash.log defconfig keep-syms-lto.c \
 	       mkimage-out.spl.mkimage mkimage.spl.mkimage imx-boot.map \
 	       itb.fit.fit itb.fit.itb itb.map spl.map mkimage-out.rom.mkimage \
-	       mkimage.rom.mkimage rom.map simple-bin.map
+	       mkimage.rom.mkimage rom.map simple-bin.map simple-bin-spi.map \
+	       idbloader-spi.img
 
 # Directories & files removed with 'make mrproper'
 MRPROPER_DIRS  += include/config include/generated spl tpl \