wcn36xx: introduce WCN36XX_HAL_AVOID_FREQ_RANGE_IND

WCN3620 firmware introduces a new async indication, we need to
add it as a known message type so we can accept it

Signed-off-by: Andy Green <andy.green@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>