net: stmmac: Fix wrong message in stmmac_probe_config_dt

Most likely a copy & paste error in referenced commit.
Restore the debug message to what it was before.

Fixes: f573c0b9

 ("stmmac: move stmmac_clk, pclk, clk_ptp_ref and stmmac_rst to platform structure")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-By: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>