net: pcs: xpcs: correctly place DW_VR_MII_DIG_CTRL1_2G5_EN

Place DW_VR_MII_DIG_CTRL1_2G5_EN with the other DW_VR_MII_DIG_CTRL1
definitions rather than in the middle of a register list.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>