brcmfmac: use brcmf_chip_name() to store name in revinfo

The chip id can either be four or five digits. For the chip name either
the hexadecimal value needs to be taken (four digits) or the decimal
value (five digits). The function brcmf_chip_name() does this conversion
so use it to store the name in driver revision info.

Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>