tty: amba-pl011: allow shared interrupt

The PL011 register space includes all necessary status bits to
determine whether a device instance requires handling in response
to an interrupt. Therefore, multiple instances of the device could
be serviced by a single shared interrupt, which is the case on BCM7211.

Signed-off-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/amba-pl011.c

@@ -1717,7 +1717,7 @@ static int pl011_allocate_irq(struct uart_amba_port *uap)
 {
 	pl011_write(uap->im, uap, REG_IMSC);
 
-	return request_irq(uap->port.irq, pl011_int, 0, "uart-pl011", uap);
+	return request_irq(uap->port.irq, pl011_int, IRQF_SHARED, "uart-pl011", uap);
 }
 
 /*