disp: msm: dp: deregister altmode notifier

Deregister the altmode notifier in the client teardown path since
the client will no longer be available to handle altmode
registration.

Change-Id: I06c6c61d4eb0b0fc9e9c1df1da4a0c86e4556de1
Signed-off-by: Tatenda Chipeperekwa <tatendac@codeaurora.org>

msm/dp/dp_altmode.c

@@ -309,6 +309,7 @@ void dp_altmode_put(struct dp_hpd *dp_hpd)
 			dp_altmode);
 
 	altmode_deregister_client(altmode->amclient);
+	altmode_deregister_notifier(altmode->dev, altmode);
 
 	kfree(altmode);
 }