wlcore needs to wait for certain events for example
for roc complete event. Usually the events are received
from the FW very fast, therefore wlcore can poll with
a short delay and if after a second the event was
not received yet poll with a long (1-5 msec) delay.

This implementation is similar to the sending of
commands to the FW.

Empirically the change reduced the wait for roc event
from ~10-40msec to 100s of usecs.

[replace udelay/msleep with usleep_range - Arik]
Signed-off-by: Yoni Divinsky <yoni.divinsky@ti.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>