brcmfmac: avoid usage of func->card->dev in sdio probe.

brcmf_ops_sdio_probe used the private_date func->card->dev to
store device data of brcmfmac sdio. This is not a good place to
store the data. Use dev of func and use func->card->sdio_func
to group the functions the driver is using.

Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>