Change the Boolean flags passed to __gsi_channel_start() and
__gsi_channel_stop() so they represent whether the request is being
made to implement suspend (versus stop) or resume (versus start).

Then stop or start the channel for suspend/resume requests only if
the hardware version indicates it should be done.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>