USB: make USB-PERSIST work after every system sleep

USB: make USB-PERSIST work after every system sleep

This patch (as1046) makes USB-PERSIST work more in accordance with
the documentation.  Currently it takes effect only in cases where the
root hub has lost power or been reset, but it is supposed to operate
whenever a power session was dropped during a system sleep.

A new hub_restart() routine carries out the duties required during a
reset or a reset-resume.  It checks to see whether occupied ports are
still enabled, and if they aren't then it clears the enable-change and
connect-change features (to prevent interference by khubd) and sets
the child device's reset_resume flag.  It also checks ports that are
supposed to be unoccupied to verify that the firmware hasn't left the
port in an enabled state.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>