Merge branch 'rpmsg-linux-5.4.y' of git://git.ti.com/rpmsg/rpmsg into rpmsg-ti-linux-5.4.y

Pull in the updated rpmsg base feature branch that adds a new
rpmsg bus driver, rpmsg-pru. The rpmsg-pru driver provides a
simple character driver interface to userspace to send messages
to the PRU remote processors on the currently supported SoCs -
AM335x, AM437x, AM57xx, 66AK2G, AM65x and J721E.

The merge also includes a workaround in the virtio rpmsg core to
properly publish the aliased 32-bit addresses for vring buffers
instead of the 64-bit physical addresses on Keystone SoCs so that
the rpmsg stack does not need any address fixups on the remote
processor side. The Keystone DSPs have a work-around on the DSP-side
software that alleviated this issue, but the fix is needed for
proper functionality of rpmsg on PRUs.

Note that the rprocs on K2 SoCs need a backport of a patch [1] in
the kernel dma layer.
  [1] https://patchwork.kernel.org/patch/11363125/

* 'rpmsg-linux-5.4.y' of git://git.ti.com/rpmsg/rpmsg

:
  rpmsg: pru: add a PRU RPMsg driver
  HACK: rpmsg: virtio_rpmsg_bus: fix up vring buffer logic for TI Keystone SoCs

Signed-off-by: Suman Anna <s-anna@ti.com>