staging: brcm80211: remove global variable from bcmsdh_sdmmc.c

The source file contained some static global variables that were
needed per device handled by the driver. They have moved to the
struct brcmf_sdio_dev for that reason.

Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>