rpmsg: glink: Do a mbox_free_channel in remove

mbox_request_channel is done in probe, so free the channel in remove.
Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/rpmsg/qcom_glink_native.c

@@ -1008,4 +1008,5 @@ void qcom_glink_native_remove(struct qcom_glink *glink)
 
 	idr_destroy(&glink->lcids);
 	idr_destroy(&glink->rcids);
+	mbox_free_channel(glink->mbox_chan);
 }