Get rid of acpi_platform_notify() which is redundant and
make device_platform_notify() in the driver core call
acpi_device_notify() and acpi_device_notify_remove() directly.

No functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>