xhci-pci: Allow host runtime PM as default for Intel Tiger Lake xHCI

In the same way as Intel Ice Lake TCSS (Type-C Subsystem) the Tiger Lake
TCSS xHCI needs to be runtime suspended whenever possible to allow the
TCSS hardware block to enter D3cold and thus save energy.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200312144517.1593-10-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>