net: fec: remove unused interrupt FEC_ENET_TS_TIMER

FEC_ENET_TS_TIMER is not checked in the interrupt routine
so there is no need to enable it.

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>