brcmfmac: allocate struct brcmf_pub instance using wiphy_new()

Rework the driver so the wiphy instance holds the main driver information
in its private buffer. Previously it held struct brcmf_cfg80211_info
instance so a bit of reorg was needed. This was done so that the wiphy
name or its parent device can be shown in debug output.

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>