dt-bindings: remoteproc: pru: Update bindings for K3 AM62x SoCs

Update the PRU remoteproc bindings for the PRU cores on AM62x SoCs.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220602101920.12504-3-kishon@ti.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>