ns16550: unify serial_omap

Unify serial_omap, and use the generic binding.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Reviewed-by: Tom Rini <trini@konsulko.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/board/ti/beagle/beagle.c b/board/ti/beagle/beagle.c
index 56e3cfe..ff317ef 100644
--- a/board/ti/beagle/beagle.c
+++ b/board/ti/beagle/beagle.c
@@ -79,7 +79,7 @@
 };
 
 U_BOOT_DEVICE(beagle_uart) = {
-	"serial_omap",
+	"ns16550_serial",
 	&beagle_serial
 };