serial: actions: add compatible string

This patch adds "actions,owl-uart" string to the owl uart driver. It
is also defined in Linux kernel.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
diff --git a/drivers/serial/serial_owl.c b/drivers/serial/serial_owl.c
index 7ead73e..539acdc 100644
--- a/drivers/serial/serial_owl.c
+++ b/drivers/serial/serial_owl.c
@@ -121,6 +121,7 @@
 
 static const struct udevice_id owl_serial_ids[] = {
 	{ .compatible =	"actions,s900-serial" },
+	{ .compatible = "actions,owl-uart" },
 	{ }
 };