PM: Prevent runtime suspend during system resume

This patch (as1591) moves the pm_runtime_get_noresume() and
pm_runtime_put_sync() calls from __device_suspend() and
device_resume() to device_prepare() and device_complete() in the PM
core.

The reason for doing this is to make sure that parent devices remain
at full power (i.e., don't go into runtime suspend) while their
children are being resumed from a system sleep.

The PCI core already contained equivalent code to serve the same
purpose.  The patch removes the duplicated code, since it is no longer
needed.  One of the comments from the PCI core gets moved into the PM
core, and a second comment is added to explain whe the _get_noresume
and _put_sync calls are present.

Change-Id: I31d311cd9d82ad53eca57d5825ae4d81c32e92b5
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Revert "USB: ensure parent device is resumed for child's system-resume"

This reverts commit de86e6482897db0006151ae9154f181e75f5ab2c.

Commit 7c8527ce ("PM: Prevent runtime suspend during system resume")
fixes the general issue of a parent device being prematurely
runtime suspended before a child device is resumed. It does so
by moving the pm_runtime_put_sync() call from the device_resume()
stage to device_complete(), which happens to act on the devices
in reverse (children before parent) order.

Thus when usb_resume() is called by device_resume(), we know its
parent will be runtime PM enabled and its usage counter is still
non-zero. This obviates the need to do an additional
pm_runtime_get_sync() before calling usb_resume_both() as the
device and its interfaces now have the opportunity to increment
the parent's power.child_count if necessary without fear of
having a runtime suspended parent.

(cherry picked from commit d48e904824ec38f9db01fcaccb527063b4c5d894)

Change-Id: I6d092c649889daf9483ed27aebe67df50d38ae91
CRs-fixed: 396041
Signed-off-by: Jack Pham <jackp@codeaurora.org>