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/Synology/ds109/ds109.c b/board/Synology/ds109/ds109.c
index c36e4d3..fe3b0eb 100644
--- a/board/Synology/ds109/ds109.c
+++ b/board/Synology/ds109/ds109.c
@@ -108,8 +108,9 @@
 
 	b_d = ns16550_calc_divisor((struct ns16550 *)CONFIG_SYS_NS16550_COM2,
 				   CONFIG_SYS_NS16550_CLK, 9600);
-	NS16550_init((struct ns16550 *)CONFIG_SYS_NS16550_COM2, b_d);
-	NS16550_putc((struct ns16550 *)CONFIG_SYS_NS16550_COM2, SOFTWARE_REBOOT);
+	ns16550_init((struct ns16550 *)CONFIG_SYS_NS16550_COM2, b_d);
+	ns16550_putc((struct ns16550 *)CONFIG_SYS_NS16550_COM2,
+		     SOFTWARE_REBOOT);
 }
 
 /* Support old kernels */