net-caif: drop redundant Kconfig entries

There is already a submenu entry that is always displayed, so there is
no need to also show a dedicated CAIF comment.

Drop dead commented code while we're here, and change the submenu text
to better match the style everyone else is using.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>