wl12xx: add automatic rx streaming triggers

When rx_streaming.interval is non-zero, use automatic rx streaming.
Enable rx streaming on the each rx/tx packet, and disable it
rx_streaming.duration msecs later.

When rx_streaming.always=0 (default), rx streaming is enabled only
when there is a coex operation.

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>