remoteproc/omap: Add device tree support

OMAP4+ SoCs support device tree boot only. The OMAP remoteproc
driver is enhanced to support remoteproc devices created through
Device Tree, support for legacy platform devices has been
deprecated. The current DT support handles the IPU and DSP
processor subsystems on OMAP4 and OMAP5 SoCs.

The OMAP remoteproc driver relies on the ti-sysc, reset, and
syscon layers for performing clock, reset and boot vector
management (DSP remoteprocs only) of the devices, but some of
these are limited only to the machine-specific layers
in arch/arm. The dependency against control module API for boot
vector management of the DSP remoteprocs has now been removed
with added logic to parse the boot register from the DT node
and program it appropriately directly within the driver.

The OMAP remoteproc driver expects the firmware names to be
provided via device tree entries (firmware-name.) These are used
to load the proper firmware during boot of the remote processor.

Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
[t-kristo@ti.com: converted to use ti-sysc framework]
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reviewed-by: Andrew F. Davis <afd@ti.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200324110035.29907-3-t-kristo@ti.com


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>