[subsystems/electrical] fix conversion of vsupply to decivolts
* Should now work correctly with <define name="VoltageOfAdc(adc)" value ="(VOLTAGE_ADC_A * adc + VOLTAGE_ADC_B )"/> with VOLTAGE_ADC_B in Volts
* Also fix VoltageOfAdc to DefaultVoltageOfAdc in board header for tiny_2.0
[subsystems/electrical] fix missing bracket
[stm32][adc] automatically use TIM1 for ADC if TIM2 is already used by RC ppm input on SERVO6
fixes #339