rtc-pcf8563-guf: Fix rtc-pcf8563-guf build
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.