Merge branch 'r8152'

Hayes Wang says:

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r8152: use mutex for hw settings

v2:
Make sure the autoresume wouldn't occur inside the mutex, otherwise
the dead lock would happen. For the purpose, adjust some code about
autosuspend/autoresume.

v1:
Use mutex to avoid that the serial hw settings would be interrupted
by other settings. Although there is no problem now, it makes the
driver more safe.
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Signed-off-by: David S. Miller <davem@davemloft.net>