of: property: Make sure child dependencies don't block probing of parent

When creating device links to proxy the sync_state() needs of child
dependencies, create SYNC_STATE_ONLY device links so that children
dependencies don't block probing of the parent.

Also, differentiate between missing suppliers of parent device vs
missing suppliers of child devices so that driver core doesn't block
parent device probing when only child supplier dependencies are missing.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20191028220027.251605-5-saravanak@google.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>