net: dsa: qca8k: fix ethtool autocast mib for big-endian systems

The switch sends autocast mib in little-endian. This is problematic for
big-endian system as the values needs to be converted.

Fix this by converting each mib value to cpu byte order.

Fixes: 5c957c7c ("net: dsa: qca8k: add support for mib autocast in Ethernet packet")
Tested-by: Pawel Dembicki <paweldembicki@gmail.com>
Tested-by: Lech Perczak <lech.perczak@gmail.com>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>