staging: brcm80211: removed iovar layer from softmac

Code cleanup. Softmac contained a redundant level of indirection, named
'iovar functionality'.

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