rptun: update rptun API parameters

[wyr-7]

Summary

remove notify_wait in remoteproc ops, rptun implements notify_wait through rpmsg_notify_wait_cb.

Impact

rptun related drivers

Testing

test in sim:rpserver, sim:rpproxy

[xiaoxiang781216]

@wyr-7 let's point open-amp to the master to get the patch which have been upstreamed.