serial: Rename .init() and .uninit() in serial_device

Rename .init() to .start() and .uninit() to .stop() in struct
serial_device. This allows aligning struct serial_device with
closer to struct stdio_dev. The real goal here is to allow
these two structures to converge together and eventually make
one to be a superset of the other.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Tom Rini <trini@ti.com>
diff --git a/drivers/serial/serial_zynq.c b/drivers/serial/serial_zynq.c
index 3832236..35bbebe 100644
--- a/drivers/serial/serial_zynq.c
+++ b/drivers/serial/serial_zynq.c
@@ -219,8 +219,8 @@
 /* Serial device descriptor */
 #define INIT_PSSERIAL_STRUCTURE(port, __name) {	\
 	  .name   = __name,			\
-	  .init   = uart_zynq##port##_init,	\
-	  .uninit = NULL,			\
+	  .start  = uart_zynq##port##_init,	\
+	  .stop   = NULL,			\
 	  .setbrg = uart_zynq##port##_setbrg,	\
 	  .getc   = uart_zynq##port##_getc,	\
 	  .tstc   = uart_zynq##port##_tstc,	\