net: slip: Clarify slip settings in Kconfig

As SLIP TAP is now the default after the commit ca0ad13a61ff5
("net: enable SLIP only on QEMU targets"), clarify the comments
and settings in various Kconfig files that talk about slip.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
3 files changed