target/riscv: Add properties for Indirect CSR Access extension

target/riscv: Add properties for Indirect CSR Access extension

This adds the properties for sxcsrind. Definitions of new registers and
implementations will come with future patches.

Signed-off-by: Kaiwen Xue <kaiwenx@rivosinc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-ID: <20250110-counter_delegation-v5-1-e83d797ae294@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>