serial: imx: Fix warning when !CONFIG_SERIAL_IMX_CONSOLE

When CONFIG_SERIAL_IMX_CONSOLE is not selected the following build warnings
appear:

drivers/tty/serial/imx.c:274:13: warning: 'imx_port_ucrs_save' defined but not used [-Wunused-function]
drivers/tty/serial/imx.c:283:13: warning: 'imx_port_ucrs_restore' defined but not used [-Wunused-function]

imx_port_ucrs_save() and imx_port_ucrs_restore() are only used when
CONFIG_CONSOLE_POLL or CONFIG_SERIAL_IMX_CONSOLE are selected, so protect these
functions declaration with a proper ifdef.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/imx.c

@@ -272,6 +272,7 @@ static inline int is_imx21_uart(struct imx_port *sport)
 /*
  * Save and restore functions for UCR1, UCR2 and UCR3 registers
  */
+#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_IMX_CONSOLE)
 static void imx_port_ucrs_save(struct uart_port *port,
 			       struct imx_port_ucrs *ucr)
 {
@@ -289,6 +290,7 @@ static void imx_port_ucrs_restore(struct uart_port *port,
 	writel(ucr->ucr2, port->membase + UCR2);
 	writel(ucr->ucr3, port->membase + UCR3);
 }
+#endif
 
 /*
  * Handle any change of modem status signal since we were last called.