Translating between ethtool advertisement settings and MII
advertisements are common operations for ethernet drivers.  This patch
adds a set of helper functions that implements the conversion.  The
patch then modifies a couple of the drivers to use the new functions.
Signed-off-by: NMatt Carlson <mcarlson@broadcom.com>
Signed-off-by: NMichael Chan <mchan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>