rockchip: Add support for veyron-mickey (Chromebit)

This adds support for the Asus Chromebit, and RK3288-based device designed
to plug directly into an HDMI monitor. The device tree file comes from
Linux v4.8.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/mach-rockchip/rk3288-board-spl.c b/arch/arm/mach-rockchip/rk3288-board-spl.c
index 185b5fd..03ac0b4 100644
--- a/arch/arm/mach-rockchip/rk3288-board-spl.c
+++ b/arch/arm/mach-rockchip/rk3288-board-spl.c
@@ -64,7 +64,8 @@
 	}
 
 fallback:
-#elif defined(CONFIG_TARGET_CHROMEBOOK_JERRY)
+#elif defined(CONFIG_TARGET_CHROMEBOOK_JERRY) || \
+		defined(CONFIG_TARGET_CHROMEBIT_MICKEY)
 	return BOOT_DEVICE_SPI;
 #endif
 	return BOOT_DEVICE_MMC1;