Modpost error on Raspbee 2 RTC installation

Raspi 4 Model B
openHAB image openhabian-pi-raspios64-202212201355-gitb2e396e-crcbd182bf5

$ uname -a
Linux openhabian 5.15.76-v8+ #1597 SMP PREEMPT Fri Nov 4 12:16:41 GMT 2022 aarch64 GNU/Linux

Hi there,

I am following this guildeline to install my raspbee 2 card. When trying to run make, I do get this error

$ makechecking deb package dependencies...
i2c-tools
build-essential
raspberrypi-kernel-headers
build rtc module...
make -C /lib/modules/5.15.76-v8+/build M=/home/openhabian/raspbee2-rtc-master modules
make[1]: Entering directory '/home/openhabian/linux-45d339389bb85588b8045dd40a00c54d01e2e711'
  MODPOST /home/openhabian/raspbee2-rtc-master/Module.symvers
ERROR: modpost: "cpu_hwcap_keys" [/home/openhabian/raspbee2-rtc-master/rtc-pcf85063.ko] undefined!
ERROR: modpost: "arm64_const_caps_ready" [/home/openhabian/raspbee2-rtc-master/rtc-pcf85063.ko] undefined!
make[2]: *** [scripts/Makefile.modpost:133: /home/openhabian/raspbee2-rtc-master/Module.symvers] Error 1
make[2]: *** Deleting file '/home/openhabian/raspbee2-rtc-master/Module.symvers'
make[1]: *** [Makefile:1815: modules] Error 2
make[1]: Leaving directory '/home/openhabian/linux-45d339389bb85588b8045dd40a00c54d01e2e711'
make: *** [Makefile:17: build] Error 2

Any hints?

Thanks