msm: ADSPRPC: Close glink channel after remote disconnected

Close glink channel only after receiving notification for remote
disconnected during subsystem restart. It will avoid race condition
to reopen the channel again before remote gets disconnected.

Change-Id: Ifa9bab946a229656a7c5440c4bd00e30c45a7140
Acked-by: Viswanatham Paduchuri <vpaduchu@qti.qualcomm.com>
Signed-off-by: Tharun Kumar Merugu <mtharu@codeaurora.org>