staging: brcm80211: move debug console related code to dhd_sdio.c

Debug console functionality is provided by dhd_sdio.c. So the related
variables and iovars should go there as well.

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