spi/bfin_spi: use nosync when disabling the IRQ from the IRQ handler

Using disable_irq() on the IRQ whose handler we are currently executing in
can easily lead to a hang.  So use the nosync variant here.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

drivers/spi/spi_bfin5xx.c

@@ -448,7 +448,7 @@ static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id)
 		/* Move to next transfer */
 		msg->state = bfin_spi_next_transfer(drv_data);
 
-		disable_irq(drv_data->spi_irq);
+		disable_irq_nosync(drv_data->spi_irq);
 
 		/* Schedule transfer tasklet */
 		tasklet_schedule(&drv_data->pump_transfers);