staging: brcm80211: remove MMC_SDIO_ABORT macro definition

The fullmac driver is always needing the code conditionalized with
MMC_SDIO_ABORT macro so the macro has been removed and the code
is always compiled in.

Signed-off-by: Arend van Spriel <arend@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>