net: qcom/emac: optimize QDF2400 SGMII RX/TX impedence values

Adjust the impedance values of the RX and TX lanes in the SGMII block
so that they are closer to optimal values.

Signed-off-by: Timur Tabi <timur@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>