msm: smsm: Add processor AWAKE signaling

This processor-awake signaling can be used by remote processors to
determine if the Apps processor is asleep and if so, if it wants to send
data to the Apps processor that would trigger a wakeup sequence.

Change-Id: I4db5891023956b27a91afc2712f9ca053f9648e5
Signed-off-by: Eric Holmberg <eholmber@codeaurora.org>