drm/bridge: dw-hdmi: set bridge's ycbcr_420_allowed flag

Set the drm_bridge's ycbcr_420_allowed flag if the YCbCr 420 output is
supported by the hardware.

Cc: Alexander Stein <[e-mail]>
Reviewed-by: Neil Armstrong <[e-mail]>
Reviewed-by: Maxime Ripard <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]
Signed-off-by: Dmitry Baryshkov <[e-mail]>

drivers/gpu/drm/bridge/synopsys/dw-hdmi.c

···
 	hdmi->bridge.of_node = pdev->dev.of_node;
 	hdmi->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
 
+	if (hdmi->version >= 0x200a)
+		hdmi->bridge.ycbcr_420_allowed = plat_data->ycbcr_420_allowed;
+
 	memset(&pdevinfo, 0, sizeof(pdevinfo));
 	pdevinfo.parent = dev;
 	pdevinfo.id = PLATFORM_DEVID_AUTO;