Merge branch 'QRTR-flow-control-improvements'

Bjorn Andersson says:

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QRTR flow control improvements

In order to prevent overconsumption of resources on the remote side QRTR
implements a flow control mechanism.

Move the handling of the incoming confirm_rx to the receiving process to
ensure incoming flow is controlled. Then implement outgoing flow
control, using the recommended algorithm of counting outstanding
non-confirmed messages and blocking when hitting a limit. The last three
patches refactors the node assignment and port lookup, in order to
remove the worker in the receive path.
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Signed-off-by: David S. Miller <davem@davemloft.net>