tty: mxser: Remove unused ASYNC_SHARE_IRQ flag

ASYNC*_SHARE_IRQ is no longer used; remove.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 7e8c27b..98d2bd1 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -2392,7 +2392,6 @@
 		if (brd->chip_flag != MOXA_OTHER_UART)
 			mxser_enable_must_enchance_mode(info->ioaddr);
 
-		info->port.flags = ASYNC_SHARE_IRQ;
 		info->type = brd->uart_type;
 
 		process_txrx_fifo(info);