The smsc911c driver puts its device into low power state when entering
system suspend. Although it doesn't update the device's runtime PM status
to RPM_SUSPENDED, which causes problems for a parent device.

In particular, when the runtime PM status of the parent is requested to be
updated to RPM_SUSPENDED, the runtime PM core prevent this, because it's
forbidden to runtime suspend a device, which has an active child.

Fix this by updating the runtime PM status of the smsc911x device to
RPM_SUSPENDED during system suspend. In system resume, let's reverse that
action by runtime resuming the device and thus also the parent.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>