USB: Add Intel Langwell USB OTG Transceiver Drive

Description:
This driver is used for Intel Langwell* USB OTG controller in Intel
Moorestown* platform. It tries to implement host/device role switch
according to OTG spec.  The actual hsot and device functions are
accomplished in modified EHCI driver and Intel Langwell USB OTG client
controller driver.

* Langwell and Moorestown are names used in development. They are not
  approved official name.

Note:
This patch is the first version Intel Langwell USB OTG Transceiver
driver. The development is not finished, and the bug fixing is on going
for some hardware and software issues. The main purpose of this
submission is for code view.

Supported features:
- Data-line Pulsing SRP
- Support HNP to switch roles
- PCI D0/D3 power management support

Known issues:
- HNP is only tested with another Moorestown platform.
- PCI D0/D3 power management support is not fully tested.
- VBus Pulsing SRP is not support in current version.

Signed-off-by: Hao Wu <hao.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>