net: sun8i_emac: Do not configure AHB2 clock

The sun8i_emac driver erroneously configures the AHB2 clock when it
assumes it is configuring the AXI gates, which is not even documented
or ever appeared in either the WiP kernel driver or Allwinner's original
driver.

As a result, AHB2 clock mux is set to an invalid setting, making the
EPHY unusable.

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>