Fix (invert/revert) Hornet-UB WPS LED state

Fix (invert/revert) Hornet-UB WPS LED state

My previous patch regarding the Hornet-UB board
(commit: beed4d82d6a0154b0cd5f7b84e2180215ace6718) actually
causes the WPS led state to be inverted. Practically this meant
that value 0 in /sys/class/led/alfa:blue:wps/brightness would
turn the LED on and any positive value (1-255) would turn it off.

The above of course is confusing and hence reverting this value
back to the way it was before beed4d82d6a0154b0cd5f7b84e2180215ace6718.

Signed-off-by: Janne Cederberg <janne.cederberg@gmail.com>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@44791 3c298f89-4303-0410-b956-a3cf2f4a3e73