IMPROVEMENT: Make Driver Config-File (_g.c) creation optional

[patrick-studer]

See #8

The Driver Config-File creation with ::hsi::utils::define_config_file is problematic, since it relays on an external definition of the _Config type.

This will break the Platform Project in Vitis Classic and end in an error.

Resolution:
Make the creation of the config file (inside the driver TCL) optional => in this case I would keep it in the TCL but bypass it:

• add a TCL variable called "generate_driver_config_file"
• Set the value by a TAG => <ENABLE_DRIVER_CONFIG>
• Surround ::hsi::utils::define_config_file with a "if $generate_driver_config_file" statement
• Extend add_software_driver with additional "-driver_config" option (boolean)
• Overwrite <ENABLE_DRIVER_CONFIG> with the value handed over by -driver_config option

Since Vitis Classic is deprecated after Vitis 2024.2, the whole software driver handling needs to be updated anyways.
Therefore, adding more automatization (e.g. auto creation of the missing _Config type definition) does not make much sense...