serial: 8250_dw: Fix typo "notifer"

There is a spelling mistake of 'notifer' in the comment which
should be 'notifier'.

Reviewed-by: Andy Shevchenko <[e-mail]>
Signed-off-by: WangYuli <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serial/8250/8250_dw.c

···
 	rate = clk_round_rate(d->clk, newrate);
 	if (rate > 0) {
 		/*
-		 * Note that any clock-notifer worker will block in
+		 * Note that any clock-notifier worker will block in
 		 * serial8250_update_uartclk() until we are done.
 		 */
 		ret = clk_set_rate(d->clk, newrate);