net: pcs: xpcs: fix incorrect steps on disable EEE

When Energy-Efficient Ethernet(EEE) is disable from the MAC side,
we need to clear the DW_VR_MII_EEE_TRN_LPI bit of DW_VR_MII_EEE_MCTRL1
register.

Fixes: 7617af3d ("net: pcs: Introducing support for DWC xpcs Energy Efficient Ethernet")
Cc: Michael Sit Wei Hong <michael.wei.hong.sit@intel.com>
Signed-off-by: Wong Vee Khee <vee.khee.wong@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>