Add support of the new serial STC8A8K64D4

[CreativeLau]

The calibrate process of new serial STC8A8K64D4 is different. In version 1.6 the MCU frequency could be adjusted up to 4 MHz only.

Have done:

1. Add 'stc8d' in option -P for STC8A8K64D4.
2. Add subclass Stc8dProtocol(Stc8Protocol).
3. Add override methods, choose_range, choose_trim, calibrate and build_options.
4. The download baud up to 460800(should add the 460800 to the definition of BAUDRATES in serial lib which is always in the local disk) To use: Set stc8d for option -P. The frequency could be adjusted from 1 to 45 MHz. Pay attention to the unit of frequency is kHz.

To do: The program_mcu method did not consider that the EEPROM in some serial could be adjusted. The EEPROM content could not be downloaded correctly, when user set the option program_eeprom_split, and give a EEPROM larger than 512 Bytes.

[IOsetting]

Does this work with STC8H3K64S4?

[CreativeLau]

Does this work with STC8H3K64S4?

I'm not sure.

[developer-ken]

Really appreciate your work on this project ! It helped me a lot.

[area-8051]

Implemented by reintegrating the work done on stcgal-patched.