8250 Serial Driver: revert extra IRQ flag definition patch

As Russell pointed out, original patch will break some serial configurations
because of the dependency of the <asm/serial.h> header file.

Revert it first and try to find out other solution later

Cc: Javier Herrero <jherrero@hvsistemas.es>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Russell King <rmk+lkml@arm.linux.org.uk>
Signed-off-by: NBryan Wu <cooloney@kernel.org>

drivers/serial/8250.c

@@ -43,7 +43,6 @@
 
 #include <asm/io.h>
 #include <asm/irq.h>
-#include <asm/serial.h>
 
 #include "8250.h"
 
@@ -93,6 +92,7 @@ static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;
  */
 #define CONFIG_HUB6 1
 
+#include <asm/serial.h>
 /*
  * SERIAL_PORT_DFNS tells us about built-in ports that have no
  * standard enumeration mechanism.   Platforms that can find all
@@ -1547,8 +1547,6 @@ static int serial_link_irq_chain(struct uart_8250_port *up)
 		i->head = &up->list;
 		spin_unlock_irq(&i->lock);
 
-		irq_flags |= SERIAL_EXTRA_IRQ_FLAGS;
-
 		ret = request_irq(up->port.irq, serial8250_interrupt,
 				  irq_flags, "serial", i);
 		if (ret < 0)

drivers/serial/8250.h

@@ -78,8 +78,3 @@ struct serial8250_config {
 #else
 #define ALPHA_KLUDGE_MCR 0
 #endif
-
-#ifndef SERIAL_EXTRA_IRQ_FLAGS
-#define SERIAL_EXTRA_IRQ_FLAGS 0
-#endif
-