staging: brcm80211: remove structure sdio_hc in brcmfmac

Most members in sdio_hc are no longer needed anymore. And fullmac
is keeping a global pointer of this structure. This patch deletes
the structure and places the useful member to a new structure
brcmf_sdio_dev. The pointer of brcmf_sdio_dev will be save in the
private driver data during sdio_probe. Therefore, we don't need to
keep the global pointer.

Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>