ide: use mutex instead of ide_cfg_sem semaphore in IDE driver

The IDE driver uses a semaphore as mutex.
Use the mutex API instead of the (binary) semaphore.

Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>