Somehow the Garz & Fricke specific PCF8563 driver rtc-pcf8563-guf was
not buildable.

On cause was a missing and unused config.h file. Remove this file from
the recipe.

Another error was due to the removal of the register resets in the
PCF8563 that should be prevented by the driver. However the buffer
variable is used later on so we cannot comment it out.