CONFIG_ATARI_ETHERNEC is not available for thedefaultarchitecture x86.
Result is shown for architecture m68k

Atari EtherNEC Ethernet support

configname: CONFIG_ATARI_ETHERNEC

Linux Kernel Configuration
└─>Platform devices
└─>Atari EtherNEC Ethernet support
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Say Y to include support for the EtherNEC network adapter for the
ROM port. The driver works by polling instead of interrupts, so it
is quite slow.

This driver also suppports the ethernet part of the NetUSBee ROM
port combined Ethernet/USB adapter.

To compile the actual ethernet driver, choose Y or M in for the NE2000
option in the network device section; the module will be called ne.