staging: brcm80211: rename ioctl command codes in dhd.h

The naming convention in the driver is to be aligned. This commit
changes the prefix used for the ioctl command codes.

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>