staging: vt6656: device_set_multi: set filter off with MACvWriteMultiAddr

set u64 mc_filter to ~0x0 multi cast filter off and write MAC_REG_MAR0 using
MACvWriteMultiAddr to replace pbyData.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>