net: Kconfig: add endif/endmenu comments

net: Kconfig: add endif/endmenu comments

Add comments on endif & endmenu blocks. This can save time
when searching & trying to understand kconfig menu dependencies.

The other endif & endmenu statements are already commented like this.

This makes it similar to drivers/net/Kconfig, which is already
commented like this.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250721020420.3555128-1-rdunlap@infradead.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>