staging: brcm80211: remove private timeout functions in fullmac

Use kernel timer macros to replace current private timeout functions
used in dhd_sdio.c

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>