enetc: remove "depends on (ARCH_LAYERSCAPE || COMPILE_TEST)"

ARCH_LAYERSCAPE isn't needed for this driver, it builds and
sends/receives traffic without this config option just fine.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>