gpu: nova-core: falcon: Add support to check if RISC-V is active

gpu: nova-core: falcon: Add support to check if RISC-V is active

Add definition for RISCV_CPUCTL register and use it in a new falcon API
to check if the RISC-V core of a Falcon is active. It is required by
the sequencer to know if the GSP's RISCV processor is active.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251110-gsp_boot-v9-13-8ae4058e3c0e@nvidia.com>