call fill_lb_framebuffer() earlier

fill_lb_framebuffer() now sets the framebuffer pointer according to
the EDID information, so it must be called before setting the tag
and size.

(credit to rminnich for this, I'm just uploading it)

Signed-off-by: David Hendricks <dhendrix@chromium.org>

Change-Id: I5ac783fa3a776eee504d39889284041d1dc2c92a
Reviewed-on: https://gerrit.chromium.org/gerrit/50012
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Commit-Queue: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/4155
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>