Merge branch 'RPMSG-WWAN-CTRL-driver'

Stephan Gerhold says:

====================
net: wwan: Add RPMSG WWAN CTRL driver

This patch series adds a WWAN "control" driver for the remote processor
messaging (rpmsg) subsystem. This subsystem allows communicating with
an integrated modem DSP on many Qualcomm SoCs, e.g. MSM8916 or MSM8974.

The driver is a fairly simple glue layer between WWAN and RPMSG
and is mostly based on the existing mhi_wwan_ctrl.c and rpmsg_char.c.

For more information, see commit message in PATCH 2/3.

I already posted a RFC for this a while ago:
https://lore.kernel.org/linux-arm-msm/YLfL9Q+4860uqS8f@gerhold.net/
and now I'm looking for some feedback for the actual changes. :)

Changes in v3:
  - PATCH 2/3: Clarify commit message
  - PATCH 3/3: Fix build error for cdc-wdm.c, use extra tx_blocking() op instead
v2: https://lore.kernel.org/netdev/20210618075243.42046-1-stephan@gerhold.net/

Changes in v2: Only in PATCH 3/3
  - Fix EPOLLOUT being always set even if poll op is defined
  - Rename poll() op -> tx_poll() since it should be only used for TX
v1: https://lore.kernel.org/netdev/20210615133229.213064-1-stephan@gerhold.net/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>