target/riscv: Invoke pmu init after feature enable

target/riscv: Invoke pmu init after feature enable

The dependant ISA features are enabled at the end of cpu_realize
in finalize_features. Thus, PMU init should be invoked after that
only. Move the init invocation to riscv_tcg_cpu_finalize_features.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-ID: <20250110-counter_delegation-v5-9-e83d797ae294@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>