net: phy: core: remove now uneeded disabling of interrupts

After commits c974bdbc3e "net: phy: Use threaded IRQ, to allow IRQ from
sleeping devices" and 664fcf123a "net: phy: Threaded interrupts allow
some simplification" all relevant code pieces run in process context
anyway and I don't think we need the disabling of interrupts any longer.

Interestingly enough, latter commit already removed the comment
explaining why interrupts need to be temporarily disabled.

On my system phy interrupt mode works fine with this patch.
However I may miss something, especially in the context of shared phy
interrupts, therefore I'd appreciate if more people could test this.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/phy.h

@@ -468,7 +468,6 @@ struct phy_device {
 	/* Interrupt and Polling infrastructure */
 	struct work_struct phy_queue;
 	struct delayed_work state_queue;
-	atomic_t irq_disable;
 
 	struct mutex lock;