riscv: Only check online cpus for emulated accesses

riscv: Only check online cpus for emulated accesses

The unaligned access checker only sets valid values for online cpus.
Check for these values on online cpus rather than on present cpus.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Fixes: 71c54b3d169d ("riscv: report misaligned accesses emulation to hwprobe")
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20240308-disable_misaligned_probe_config-v9-2-a388770ba0ce@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>