net: nps_enet: Fix PCS reset

During commit b54b8c2d
 ("net: ezchip: adapt driver to little endian architecture")
 adapting to little endian architecture,
 zeroing of controller was left out.

Signed-off-by: Elad Kanfi <eladkan@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>