If the parent is still suspended when driver probe is
attempted, the result may be failure.

For example, if the parent is a PCI MFD device that has been
suspended when we try to probe our device, any register
reads will return 0xffffffff.

To fix the problem, making sure the parent is always awake
before attempting driver probe.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>