serial: 8250_dw: add ACPI ID for Intel BayTrail

This is the same controller as on Intel Lynxpoint but the
ACPI ID is different.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>