drm/bridge-connector: Sync supported_formats with computed ycbcr_420_allowed

The case of having an HDMI bridge in the pipeline which advertises
YUV420 capability via its ->supported_formats and a non-HDMI one that
didn't enable ->ycbcr_420_allowed, is incorrectly handled because
supported_formats is passed as is to the helper initializing the HDMI
connector.

Ensure HDMI_COLORSPACE_YUV420 is removed from the bitmask passed to
drmm_connector_hdmi_init() when connector's ->ycbcr_420_allowed flag
ends up not being set.

Fixes: 3ced1c68 ("drm/display: bridge_connector: handle ycbcr_420_allowed")
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241224-bridge-conn-fmt-prio-v4-2-a9ceb5671379@collabora.com


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>