serial: Use default_serial_puts() in drivers

Replace the in-place ad-hoc implementation of serial_puts() within
the drivers with default_serial_puts() call. This cuts down on the
code duplication quite a bit.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Marek Vasut <marek.vasut@gmail.com>
Cc: Tom Rini <trini@ti.com>
diff --git a/arch/powerpc/cpu/mpc85xx/serial_scc.c b/arch/powerpc/cpu/mpc85xx/serial_scc.c
index fe9af55..6345362 100644
--- a/arch/powerpc/cpu/mpc85xx/serial_scc.c
+++ b/arch/powerpc/cpu/mpc85xx/serial_scc.c
@@ -220,13 +220,6 @@
 	tbdf->cbd_sc |= BD_SC_READY;
 }
 
-static void mpc85xx_serial_puts(const char *s)
-{
-	while (*s) {
-		serial_putc (*s++);
-	}
-}
-
 static int mpc85xx_serial_getc(void)
 {
 	volatile cbd_t		*rbdf;
@@ -268,7 +261,7 @@
 	.stop	= NULL,
 	.setbrg	= mpc85xx_serial_setbrg,
 	.putc	= mpc85xx_serial_putc,
-	.puts	= mpc85xx_serial_puts,
+	.puts	= default_serial_puts,
 	.getc	= mpc85xx_serial_getc,
 	.tstc	= mpc85xx_serial_tstc,
 };