Get true visible area when querying frame buffer device

The visible area is obtained by calling ply_monitor_setup().  This is
the area that represents the actual screen size.

BUG=chrome-os-partner:16339
TEST=Plug in external HDMI monitor on Daisy, boot up, splash screen
should be centered.

Change-Id: Ia71c6f49050bdbe6c3e5c51c6b79bf8b33bb9298
Signed-off-by: Simon Que <sque@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/38500
Reviewed-by: St├ęphane Marchesin <marcheu@chromium.org>
5 files changed