spcom: ignore CONNECTED notification while closing the channel

The spcom_notify_state() callback, is called by glink driver.
In case of calling glink_open() and shortly after that calling
glink_close(), the glink might notify of channel CONNECTED while
glink_closed() is called.
Avoid updating the glink channel upon CONNECTED event, if in process
of closing the channel.

Change-Id: If5cbec1a7d1653c56b5350afcd3cee61e1ae05fa
Signed-off-by: Amir Samuelov <amirs@codeaurora.org>