dt-bindings: remoteproc: k3-dsp: Update bindings for J721S2 SoCs

dt-bindings: remoteproc: k3-dsp: Update bindings for J721S2 SoCs

The TI K3 J721S2 SoCs have two TMS320C71x DSP subsystems, and does not
have any TMS320C66x DSP subsystems. The C71x DSP subsystem in J721S2
SoCs is a similar to the C71x DSP on J721e with some minor core IP updates.

Compatible info is updated for intuitvely matching to the new J721S2
SoCs.

Signed-off-by: Hari Nagalla <hnagalla@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211122122726.8532-3-hnagalla@ti.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>