of/fdt: fix aliases with baudrate in earlycon

Many boards use an alias in the stdout-path specification along
with console options after a colon (e.g. serial0:115200n8). When
using earlycon, this specification currently does not work. While
fdt_path_offset supports alias resolution, it does not remove the
console options by itself. Use the fdt_path_offset_namelen variant
and provide the length of the alias to enable aliases with console
options in the stdout-path.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Rob Herring <robh@kernel.org>

drivers/of/fdt.c

@@ -813,8 +813,11 @@ static int __init early_init_dt_scan_chosen_serial(void)
 	if (!p || !l)
 		return -ENOENT;
 
+	/* Remove console options if present */
+	l = strchrnul(p, ':') - p;
+
 	/* Get the node specified by stdout-path */
-	offset = fdt_path_offset(fdt, p);
+	offset = fdt_path_offset_namelen(fdt, p, l);
 	if (offset < 0)
 		return -ENODEV;