[MIPS] TXx9: Unify serial_txx9 setup

* Unify calling of early_serial_txx9_setup.
* Use dedicated serial clock on RBTX4938.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/txx9/rbtx4927/setup.c b/arch/mips/txx9/rbtx4927/setup.c
index 962ada5..0d39baf 100644
--- a/arch/mips/txx9/rbtx4927/setup.c
+++ b/arch/mips/txx9/rbtx4927/setup.c
@@ -212,7 +212,7 @@
 	set_io_port_base(KSEG1 + RBTX4927_ISA_IO_OFFSET);
 #endif
 
-	tx4927_setup_serial();
+	tx4927_sio_init(0, 0);
 #ifdef CONFIG_SERIAL_TXX9_CONSOLE
 	argptr = prom_getcmdline();
 	if (!strstr(argptr, "console="))