amd-xgbe: Use disable_irq_nosync when in IRQ context

The disable_irq_nosync function, not the disable_irq function, must be
used to disable the DMA channel interrupt from within the interrupt
service routine. Change the disable_irq call to disable_irq_nosync.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>