xhci: Add Lynx Point LP to list of Intel switchable hosts

Like Lynx Point, Lynx Point LP is also switchable.  See
1c12443a for more details.

This patch should be backported to stable kernels as old as 3.0,
that contain commit 69e848c2
"Intel xhci: Support EHCI/xHCI port switching."

Signed-off-by: Russell Webb <russell.webb@linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org