drm/i915: Move VLV HDMI lane reset work around logic to intel_dpio_phy.c

This moves the last phy specific code from the encoders to the phy
specific file.

Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Jim Bride <jim.bride@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461761065-21195-11-git-send-email-ander.conselvan.de.oliveira@intel.com