atm/fore200e: Delete unused 'fore200e_boards'

This list looks like it's been unused since the OF conversion in
2008 in

commit 826b6cfc ("fore200e: Convert over to pure OF driver.")

This also means we can remove the 'entry' member for the list.

Build tested only.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240503001822.183061-1-linux@treblig.org


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