ACPI / platform: use ACPI device name instead of _HID._UID

Using _UID makes the ACPI platform bus code depend on BIOS to get it
right. If it doesn't we fail to create the platform device as the name
should be unique.

The ACPI core already makes a unique name when it first creates the ACPI
device so we can use that same name as the platform device name instead of
trusting that the BIOS sets the _UIDs correctly.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>