Hardware engineers confirmed that writing to it has no effect, as implied
by the FIXME comment.

v2: Also remove comment from bxt_ddi_phy_verify_state(). (Imre)
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1478069096-11209-1-git-send-email-ander.conselvan.de.oliveira@intel.com