staging: brcm80211: remove struct brcmf_sdioh_driver from brcmfmac

brcmf_sdioh_driver is a legacy bus driver interface we dont need
any more.

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>