wil6210: increase firmware ready timeout

Firmware ready event may take longer than
current timeout in some scenarios, for example
with multiple RFs connected where each
requires an initial calibration.

Increase the timeout to support these scenarios.

Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>