drm/bridge/synopsys: dw-hdmi: Enable workaround for v1.32a

Allwinner SoCs have dw hdmi controller v1.32a which exhibits same
magenta line issue as i.MX6Q and i.MX6DL. Enable workaround for it.

Tests show that one iteration is enough.

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180214200906.31509-4-jernej.skrabec@siol.net