serial: sc16is7xx: remove unused line structure member

Now that the driver has been converted to use one regmap per port, the line
structure member is no longer used, so remove it.

Fixes: 3837a03 ("serial: sc16is7xx: improve regmap debugfs by using one regmap per port")
Cc:  <stable@vger.kernel.org>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231211171353.2901416-4-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/sc16is7xx.c

@@ -322,7 +322,6 @@ struct sc16is7xx_one_config {
 
 struct sc16is7xx_one {
 	struct uart_port		port;
-	u8				line;
 	struct regmap			*regmap;
 	struct kthread_work		tx_work;
 	struct kthread_work		reg_work;
@@ -1552,7 +1551,6 @@ static int sc16is7xx_probe(struct device *dev,
 		     SC16IS7XX_IOCONTROL_SRESET_BIT);
 
 	for (i = 0; i < devtype->nr_uart; ++i) {
-		s->p[i].line		= i;
 		/* Initialize port data */
 		s->p[i].port.dev	= dev;
 		s->p[i].port.irq	= irq;