Set the connector's kernel device as the parent for the aux kernel
device. This allows udev rules to access connector attributes when
creating symlinks to aux devices.

Cc: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Leo Li <sunpeng.li@amd.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190723232808.28128-4-sunpeng.li@amd.com