Allow sub-integer duty cycle percentage for LGPIOPin

Currently, the method `_set_state(value)` of `LGPIOPin` forces the input duty cycle to a whole percentage:

```python
self._pwm = (freq, int(value * 100))
```

This leads to poor angular resolution when trying to use a `Servo` instance with a LGPIO pin factory.

Simply removing call to int() should improve performance: 

```python
self._pwm = (freq, value * 100)
```


