staging: wilc1000: simplify semaphore wrapper

The driver has its own API for semaphores. This should
be replaced with mutexes and completions, but for the moment
we can start by removing the obviously unused parts.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>