next to the broadcom firmware for the OP's wifi chip on the Z83 II (brcmfmac43455-sdio.bin), you also need to supply the nvram text file.
A 'dmesg' would probably show that it cannot find it:
===> brcmfmac mmc1:0001:1: Direct firmware load for brcm/brcmfmac43455-sdio.txt failed with error -2
Copy the attached .txt file to the same folder (/lib/firmware/brcm).
gkkpch Thanks for the tip, but its not that simple I get this error message: