Revert 9f62a472 ("video: Remove duplicate cursor-positioning function")

This reverts commit 9f62a472.

The changes here aren't quite right, and on platforms such as Raspberry
Pi where we can have both serial and video output, the change above
causes output to change. This can be seen as the hush tests we have now
fail.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>