QMX6: Move initialization of CLKO2 into separate function
phy/micrel: Fix detection of KSZ9021 and KSZ9031

The PHY ID register contains the chip revision in the lowest four bits. This
patch uses the correct PHY ID mask and sets the lower four bits to zero in the
PHY ID defines (PHY_ID_KSZ9021 and PHY_ID_KSZ9031).