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/leon2/serial.c b/arch/sparc/cpu/leon2/serial.c
index 16fffb6..40d5b01 100644
--- a/arch/sparc/cpu/leon2/serial.c
+++ b/arch/sparc/cpu/leon2/serial.c
@@ -105,13 +105,6 @@
 	leon2_serial_putc_raw(c);
 }
 
-static void leon2_serial_puts(const char *s)
-{
-	while (*s) {
-		serial_putc(*s++);
-	}
-}
-
 static int leon2_serial_getc(void)
 {
 	LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
@@ -172,7 +165,7 @@
 	.stop	= NULL,
 	.setbrg	= leon2_serial_setbrg,
 	.putc	= leon2_serial_putc,
-	.puts	= leon2_serial_puts,
+	.puts	= default_serial_puts,
 	.getc	= leon2_serial_getc,
 	.tstc	= leon2_serial_tstc,
 };