net: fec: remove reference to nonexistent CONFIG_GILBARCONAP option

net: fec: remove reference to nonexistent CONFIG_GILBARCONAP option

The CONFIG_GILBARCONAP option has never been defined by the kernel, but
is referred to by drivers/net/ethernet/freescale/fec_main.c. Remove this
reference to eliminate dead code.

Discovered while searching for CONFIG_* symbols referenced in code but
not defined in any Kconfig file.

Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Reviewed-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260609045200.32606-1-enelsonmoore@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>