target/riscv: Fix the predicate functions for mhpmeventhX CSRs

target/riscv: Fix the predicate functions for mhpmeventhX CSRs

mhpmeventhX CSRs are available for RV32. The predicate function
should check that first before checking sscofpmf extension.

Fixes: 14664483457b ("target/riscv: Add sscofpmf extension support")
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-ID: <20240711-smcntrpmf_v7-v8-2-b7c38ae7b263@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>