ramips: improve Skylab SKW92A support

ramips: improve Skylab SKW92A support

Use the generic board detection instead of the target specific one as
all recent additions are doing.

Add the wireless led according the gpio number from the datasheet.
Rename the board part of the leds to match the name used for the
compatible string. Finally, do not hijack the wps led for boot status
indication longer than necessary.

Merge userspace config into existing cases.

Include the manufacture Name in the dts model string.

Signed-off-by: Mathias Kresin <dev@kresin.me>
(backported from 8ec1a66c34d85bdd13754e4171333a763aaf0a00)