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/sparc/cpu/leon3/serial.c b/arch/sparc/cpu/leon3/serial.c
index c4f3ee8..838d451 100644
--- a/arch/sparc/cpu/leon3/serial.c
+++ b/arch/sparc/cpu/leon3/serial.c
@@ -99,13 +99,6 @@
 	leon3_serial_putc_raw(c);
 }
 
-static void leon3_serial_puts(const char *s)
-{
-	while (*s) {
-		serial_putc(*s++);
-	}
-}
-
 static int leon3_serial_getc(void)
 {
 	if (!leon3_apbuart)
@@ -146,7 +139,7 @@
 	.stop	= NULL,
 	.setbrg	= leon3_serial_setbrg,
 	.putc	= leon3_serial_putc,
-	.puts	= leon3_serial_puts,
+	.puts	= default_serial_puts,
 	.getc	= leon3_serial_getc,
 	.tstc	= leon3_serial_tstc,
 };