net: asix: autoneg will set WRITE_MEDIUM reg

From: Grant Grundler <grundler@chromium.org>

The miii_nway_restart() causes a PHY link change activity and
ax88772_link_reset will be called. link_reset will set
AX_CMD_WRITE_MEDIUM_MODE register correctly.

The asix_write_medium_mode in reset() fills in a default value to the register
which may be different from the negotiation result. So do this first.

Ignore the ret value since it's ignored in XXX_link_reset() functions.

Signed-off-by: Grant Grundler <grundler@google.com>
Signed-off-by: Robert Foss <robert.foss@collabora.com>
Tested-by: Robert Foss <robert.foss@collabora.com>
Signed-off-by: David S. Miller <davem@davemloft.net>