Wake IRQ is optional interrupt that can be wired up on SoundWire controller
instances like RX path along with MBHC(Multi Button Headset connection).
Document this in bindings.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220228172528.3489-3-srinivas.kandagatla@linaro.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>