dsa: add support for the Marvell 88E6095/6095F switch chips

Add support for the Marvell 88E6095/6095F switch chips.  These
chips are similar to the 88e6131, so we can add the support to
mv88e6131.c easily.

Thanks to Gary Thomas <gary@mlbassoc.com> and Jesper Dangaard
Brouer <hawk@diku.dk> for testing various patches.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Tested-by: Gary Thomas <gary@mlbassoc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>