rockchip: spl-boot-order: do not attempt to access fdt if OF_PLATDATA

gd->fdt_blob is null if using OF_PLATDATA in SPL, which causes a hang
after f0921f5098 ("fdt: Sync up to the latest libfdt").
We use the same test that is used in spl_common_init on whether to call
fdtdec_setup to unconditionally avoid linking in the fdt-using code
when not necessary and thus reduce SPL size.

Signed-off-by: Urja Rannikko <urjaman@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/mach-rockchip/spl-boot-order.c b/arch/arm/mach-rockchip/spl-boot-order.c
index c2e4023..94673f3 100644
--- a/arch/arm/mach-rockchip/spl-boot-order.c
+++ b/arch/arm/mach-rockchip/spl-boot-order.c
@@ -99,6 +99,12 @@
 
 void board_boot_order(u32 *spl_boot_list)
 {
+	/* In case of no fdt (or only platdata), use spl_boot_device() */
+	if (!CONFIG_IS_ENABLED(OF_CONTROL) || CONFIG_IS_ENABLED(OF_PLATDATA)) {
+		spl_boot_list[0] = spl_boot_device();
+		return;
+	}
+
 	const void *blob = gd->fdt_blob;
 	int chosen_node = fdt_path_offset(blob, "/chosen");
 	int idx = 0;