bonding: use siocdevprivate

The bonding driver supports two command codes for each operation: one
in the SIOCDEVPRIVATE range and another one with the same definition
but a unique command code.

Only the second set currently works in compat mode, as the ifr_data
expansion overwrites part of the ifr_slave field.

Move the private ones into ndo_siocdevprivate and change the
implementation to call the other function.  This makes both version
work correctly.

Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>