net: stmmac: dwmac-sun8i: Use reset_control_reset

Use the appropriate function instead of reimplementing it,
and update the error message to match the code.

Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: David S. Miller <davem@davemloft.net>