Pull rpmsg updates from Bjorn Andersson:
 "Argument validation in public functions, function stubs for
  COMPILE_TEST-ing clients, preparation for exposing rpmsg endponts
  to user space and minor Qualcomm SMD fixes"

* tag 'rpmsg-v4.10' of git://github.com/andersson/remoteproc:
  dt-binding: soc: qcom: smd: Add label property
  rpmsg: qcom_smd: Correct return value for O_NONBLOCK
  rpmsg: Provide function stubs for API
  rpmsg: Handle invalid parameters in public API
  rpmsg: Support drivers without primary endpoint
  rpmsg: Introduce a driver override mechanism
  rpmsg: smd: Reduce restrictions when finding channel