bug: dynamic bit count selection doesn't work

1. file `energy_meter/core.h`
2. When the `ADC_RES` is equal to ADC_RES_10BIT the first entry is always true. Thas is wrong.

```
#define ADC_RES         ADC_RES_12BIT   /* ADC resolution */
#if ADC_RES == ADC_RES_12BIT
#define ADC_BIT         12U
#elif ADC_RES == ADC_RES_10BIT
#define ADC_BIT        10U
#endif
```