zd1211rw: reset device when CR_BCN_FIFO_SEMAPHORE freezes in beacon setup

When driver fails to acquire device semaphore lock, device usually
freezes soon afterwards. So failing to acquire lock indicates us that
not everything is going right in device/fw. So reset device when
this happens.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>