staging: brcm80211: remove duplicate set sb window address function

In fullmac, brcmf_sdbrcm_set_siaddr_window and brcmf_sdcard_set_sbaddr_window
have identical fucntionality. Remove the one in dhd_sdio.c

Reported-by: Rafal Milecki <zajec5@gmail.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Roland Vossen <rvossen@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>