[PATCH] net: remove CONFIG_NET_CBUS conditional for NS8390

Don't bother testing for CONFIG_NET_CBUS ("NEC PC-9800 C-bus cards"); it went
out with the rest of PC98 subarch.

Signed-off-by: Arthur Othieno <apgo@patchbomb.org>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>