net: gianfar: remove misuse of IRQF_NO_SUSPEND flag

The device is set as wakeup capable using proper wakeup API but the
driver misuses IRQF_NO_SUSPEND to set the interrupt as wakeup source
which is incorrect.

This patch removes the use of IRQF_NO_SUSPEND flags replacing it with
enable_irq_wake instead.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Claudiu Manoil <claudiu.manoil@freescale.com>
Cc: Kevin Hao <haokexin@gmail.com>
Cc: netdev@vger.kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>