tty: serial_core: Export uart_console_device so it can be used by modules

In order to support serial console w/ SERIAL_QCOM_GENI=m,
we need to export the uart_console_device() symbol so things
will build

Cc: Todd Kjos <tkjos@google.com>
Cc: Alistair Delva <adelva@google.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Amit Pundir <amit.pundir@linaro.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
Link: https://lore.kernel.org/r/20200107010311.58584-1-john.stultz@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/serial_core.c

@@ -2603,6 +2603,7 @@ struct tty_driver *uart_console_device(struct console *co, int *index)
 	*index = co->index;
 	return p->tty_driver;
 }
+EXPORT_SYMBOL_GPL(uart_console_device);
 
 static ssize_t uart_get_attr_uartclk(struct device *dev,
 	struct device_attribute *attr, char *buf)