drm/edid: Reduce horizontal timings for pixel replicated modes

Pixel replicated modes should be non-2x horizontal timings and pixel
replicated by the HW across the HDMI cable at 2X pixel clock. Current
horizontal resolution of 1440 does not allow pixel duplication to
occur and scaling artifacts occur on the TV. HDMI certification
7-26 currently fails for all pixel replicated modes. This change will
allow HDMI certification with 480i/576i modes once pixel replication
is turned on.

Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>