target/riscv: mcountinhibit, mcounteren, scounteren, hcounteren is 32-bit

target/riscv: mcountinhibit, mcounteren, scounteren, hcounteren is 32-bit

mcountinhibit, mcounteren, scounteren and hcounteren must always be 32-bit
by privileged spec

Signed-off-by: Vadim Shakirov <vadim.shakirov@syntacore.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-ID: <20240202113919.18236-1-vadim.shakirov@syntacore.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>