staging: brcm80211: remove nvram related source files

nvram.c is intended for devices with configuration stored in flash. This
is not required for the softmac driver nor the fullmac driver so it has
been removed.

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