net: fec: Remove non-Coldfire platform IDs

All i.MX platforms (non-Coldfire) use DT nowadays, so their platform ID
entries can be removed.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20231017063419.925266-3-alexander.stein@ew.tq-group.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>