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

Pull in the remoteproc topic branch that adds the support for the dual-core
Arm Cortex R5F cores present within a R5F subsystem for AM65x & J721E SoCs
through a new TI K3 R5F remoteproc driver. The remoteproc driver is somewhat
different from other existing remoteproc drivers - it requires two or more
carveout reserved memory nodes to be defined. The firmwares are expected
to use the TCMs for boot-strapping themselves to be able to execute from
DDR memory.

Supported features include functionality for both LockStep mode and Split
modes, loading into on-chip internal memories etc. The RPMsg stack is
supported through OMAP Mailboxes much like the OMAP remoteproc driver.
The driver also supports a new 'IPC-only' mode where the remote processors
have been already booted by bootloader and the kernel driver only
establishes the IPC/rpmsg. There is no support for advanced features
such as Power Management or Error Recovery.

The support required couple of enhancements to the remoteproc core -
new .prepare() and .unprepare() ops were added that are needed by the
R5F remoteproc driver for managing its reset for loading into TCMs.

The merge also includes a mailbox tree merge to bring in the sub-mailboxes
needed to communicate with various remote processors on the AM65x and J721E
SoCs. The required TI-SCI processor control support and the support for the
MCU SRAM through the mmio-sram driver is already upstream and present in
vanilla 5.4 kernel itself.

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

: (31 commits)
  remoteproc/k3-r5: add support for IPC-only mode for all R5Fs
  remoteproc: add infrastructure support to allow pre-loaded remoteprocs
  TEMP: samples/rpmsg: add compatible to support PDK IPC firmware images
  arm64: dts: ti: k3-j721e: Add aliases for R5F rproc nodes
  arm64: dts: ti: k3-j721e-som-p0: Reserve memory for IPC between RTOS cores
  arm64: dts: ti: k3-j721e-som-p0: Add DDR carveout memory nodes for R5Fs
  arm64: dts: ti: k3-j721e-common-proc-board: Add mailboxes to R5Fs
  arm64: dts: ti: k3-j721e-main: Configure MAIN R5FSS0 for Split-mode
  arm64: dts: ti: k3-j721e-main: Add MAIN domain R5F cluster nodes
  arm64: dts: ti: k3-j721e-mcu: Add MCU domain R5F cluster node
  arm64: dts: ti: k3-am65-mcu: Reserve some MCU SRAM for MCU R5F0
  arm64: dts: ti: k3-am65: Add aliases for R5F rproc nodes
  TEMP: arm64: dts: ti: k3-am654-base-board: Increase reserve memory for RTOS IPC
  arm64: dts: ti: k3-am654-base-board: Reserve memory for IPC between R5F cores
  arm64: dts: ti: k3-am654-base-board: Add DDR carveout memory nodes for R5Fs
  arm64: dts: ti: k3-am654-base-board: Add mailboxes to R5Fs
  arm64: dts: ti: k3-am65-mcu: Add MCU domain R5F cluster node
  remoteproc/k3-r5: add a trace to print missing ids
  remoteproc/k3-r5: Add loading support for on-chip SRAM regions
  remoteproc/k3-r5: Initialize TCM memories for ECC
  ...

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