serial: Rename ns16550 functions to lower case

Lower case should be used for function names. Update this driver and its
callers accordingly.

Signed-off-by: Simon Glass <sjg@chromium.org>

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
diff --git a/board/freescale/mpc8315erdb/mpc8315erdb.c b/board/freescale/mpc8315erdb/mpc8315erdb.c
index fff8699..05b983a 100644
--- a/board/freescale/mpc8315erdb/mpc8315erdb.c
+++ b/board/freescale/mpc8315erdb/mpc8315erdb.c
@@ -220,7 +220,7 @@
 void board_init_f(ulong bootflag)
 {
 	board_early_init_f();
-	NS16550_init((struct ns16550 *)(CONFIG_SYS_IMMR + 0x4500),
+	ns16550_init((struct ns16550 *)(CONFIG_SYS_IMMR + 0x4500),
 		     CONFIG_SYS_NS16550_CLK / 16 / CONFIG_BAUDRATE);
 	puts("NAND boot... ");
 	timer_init();
@@ -240,9 +240,9 @@
 		return;
 
 	if (c == '\n')
-		NS16550_putc((struct ns16550 *)(CONFIG_SYS_IMMR + 0x4500), '\r');
+		ns16550_putc((struct ns16550 *)(CONFIG_SYS_IMMR + 0x4500), '\r');
 
-	NS16550_putc((struct ns16550 *)(CONFIG_SYS_IMMR + 0x4500), c);
+	ns16550_putc((struct ns16550 *)(CONFIG_SYS_IMMR + 0x4500), c);
 }
 
 #endif /* CONFIG_NAND_SPL */