arm: Check for valid FDT after console is up

When using CONFIG_OF_CONTROL, add a check that we have a valid FDT
and panic() if not. This must be done after the console is ready.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

arch/arm/lib/board.c

@@ -293,6 +293,14 @@ void board_init_f(ulong bootflag)
 		}
 	}
 
+#ifdef CONFIG_OF_CONTROL
+	/* For now, put this check after the console is ready */
+	if (fdtdec_prepare_fdt()) {
+		panic("** CONFIG_OF_CONTROL defined but no FDT - please see "
+			"doc/README.fdt-control");
+	}
+#endif
+
 	debug("monitor len: %08lX\n", gd->mon_len);
 	/*
 	 * Ram is setup, size stored in gd !!