BACKPORT: driver core: Skip unnecessary work when device doesn't have sync_state()

A bunch of busy work is done for devices that don't have sync_state()
support. Stop doing the busy work.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200221080510.197337-4-saravanak@google.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 77036165d8bcf7c7b2a2df28a601ec2c52bb172d)
Bug: 151865289
Change-Id: Id513185be93c036150ffd7156104f898fec70c11
(cherry picked from commit a27d26af7d122f04734a31e16aefbc56de68ae29)
Bug: 265875490