drivers: net: xgene: fix sharing of irqs

Since hardware doesn't allow sharing of interrupts,
this patch fixes the same by removing IRQF_SHARED flag.

Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Tested-by: Toan Le <toanle@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>