firmware: xilinx: Add RPU configuration APIs

This patch adds APIs to access to configure RPU and its
processor-specific memory.

That is query the run-time mode of RPU as either split or lockstep as well
as API to set this mode. In addition add APIs to access configuration of
the RPUs' tightly coupled memory (TCM).

Signed-off-by: Ben Levinsky <ben.levinsky@amd.com>
Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
Acked-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/20221114233940.2096237-6-tanmay.shah@amd.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>