TV Out refresh rate was half of the specification for almost all modes.
Due to this reason pixel clock was so low for some modes causing flickering screen.
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Keith Packard <keithp@keithp.com>