target/riscv: Add implied rule for counter delegation extensions

target/riscv: Add implied rule for counter delegation extensions

The counter delegation/configuration extensions depend on the following
extensions.

1. Smcdeleg - To enable counter delegation from M to S
2. S[m|s]csrind - To enable indirect access CSRs

Add an implied rule so that these extensions are enabled by default
if the sscfg extension is enabled.

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-v5-10-e83d797ae294@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>