usb: dwc3: pci: Allow Elkhart Lake to utilize DSM method for PM functionality

Similar to some other IA platforms, Elkhart Lake too depends on the
PMU register write to request transition of Dx power state.

Thus, we add the PCI_DEVICE_ID_INTEL_EHLLP to the list of devices that
shall execute the ACPI _DSM method during D0/D3 sequence.

[heikki.krogerus@linux.intel.com: included Fixes tag]

Fixes: dbb0569d ("usb: dwc3: pci: Add Support for Intel Elkhart Lake Devices")
Cc: stable@vger.kernel.org
Signed-off-by: Raymond Tan <raymond.tan@intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>