ARM: kirkwood: mark guruplug sdio as non-removable

Globalscale Guruplug has AW-GH381 WiFi/BT on sdio which is always
present and cannot be detected in any way. Therefore, mark the node
as non-removable instead of broken-cd. While at it, also put a note
about connected WiFi/BT chip above.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>