net: sun8i_emac: Drop redundant and incorrect setting of syscon register

In sun8i_emac_board_setup, the driver partially configures the syscon
register for H3 EPHY. However, the settings are incomplete, and
completely unusable. The correct settings are later set in
sun8i_emac_set_syscon, but the incorrect CLK_SEL setting persists.

It is incorrect to use CLK_SEL to select 25 MHz, as the SoC does not
have a 25 MHz clock the EPHY can use.

This patch removes the setting of the syscon register in board_setup,
and also moves set_syscon above mdio_init. While mdio_init does not
access the PHY, it is better to have the PHY parameters setup before
the MDIO bus is registered.

Fixes: a29710c5 ("net: Add EMAC driver for H3/A83T/A64 SoCs.")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>