phy: atheros: Use ar8035_config for AR8031

phy: atheros: Use ar8035_config for AR8031

Commit 08ad9b068afb88 (" ar8031: modify the config func of ar8031 to
ar8021_config") selected 'ar8021_config' as the configuration function
for AR8031.

The correct would be to use 'ar8035_config' instead as AR8031/AR8035
have the same programming model and even share the same phy driver
in the linux kernel: drivers/net/phy/at803x.c.

Tested on a mx6qsabresd and wandboard, which now can work without
any PHY setup code in the board files.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>