staging: brcm80211: always enable code for PLATFORM_BUS functionality

Some code is conditionally compiled in upon defintion of PLATFORM_BUS
macro. This patch will have it compiled in unconditionally.

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>