staging: brcm80211: remove wrapper functions in bcmsdh_sdmmc.c

Use brcmf_sdioh_request_byte directly instead of calling
brcmf_sdioh_cfg_read and brcmf_sdioh_cfg_write in brcmfmac

Reviewed-by: Arend van Spriel <arend@broadcom.com>
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>