backend-drm: fix drm find wrong connector
In a multi-GPU environment, different cards may contain connectors with the same ID, and drm_head_find_by_connector just use the connector_id to find the connector, it may find the wrong connector.Fix this by find the connector based on the card ID and connector_id.
For drm_writeback_find_by_connector
and drm_output_deinit
functions, they
need to operate on a specified DRM device, not always the b->drm
.
Signed-off-by: Zhou Liang 174381115@qq.com