remoteproc/rpmsg: new subsystem

This new subsystem provides a common way to talk to secondary processors
on an SoC, e.g. a DSP, GPU or service processor, using virtio as the
transport. In the long run, it should replace a few dozen vendor
specific ways to do the same thing, which all never made it into the
upstream kernel. There is a broad agreement that rpmsg is the way to
go here and several vendors have started working on replacing their
own subsystems.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Merge tag 'rpmsg-fixes-and-more-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc into next/rpmsg

Fixing and cleaning up several remoteproc and rpmsg issues.

In addition, remoteproc's resource table is converted to a collection
of type-value members, instead of a rigid array of homogeneous structs.

This enables remoteproc to support registration of generic virtio devices,
and not only a single VIRTIO_ID_RPMSG virtio device.

But perhaps more importantly, the resource table overhaul makes it possible
to easily extend it in the future without breaking older images (simply by
defining a new member type, while continuing to support older types).

* tag 'rpmsg-fixes-and-more-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc:
  remoteproc: cleanup resource table parsing paths
  remoteproc: remove the hardcoded vring alignment
  remoteproc/omap: remove the mbox_callback limitation
  remoteproc: remove the single rpmsg vdev limitation
  remoteproc: safer boot/shutdown order
  remoteproc: remoteproc_rpmsg -> remoteproc_virtio
  remoteproc: resource table overhaul
  rpmsg: fix build warning when dma_addr_t is 64-bit
  rpmsg: fix published buffer length in rpmsg_recv_done
  rpmsg: validate incoming message length before propagating
  rpmsg: fix name service endpoint leak
  remoteproc/omap: two Kconfig fixes
  remoteproc: make sure we're parsing a 32bit firmware