rpmsg: glink: Revert enable irq wake for glink interrupt

'Commit 55a2eec5 ("rpmsg: glink: Enable irq wake for glink
interrupt")' was added to support device wakeup from suspended
state in case of incoming message/call in SA515 target. But it
is breaking LPM of trinket target hence revert this change.

Change-Id: Ia4e885ede81cd97ff91c521ca3ac4beefe3a6d04
Signed-off-by: Arun Prakash <app@codeaurora.org>
Signed-off-by: Marco Zhang <zhangx@codeaurora.org>